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Nortel TN 1X/1C
By: Sudhir Warier
NORTEL PRODUCT FAMILY
NORTEL SDH Transmission Equipment
Optical, Electrical and Radio Transmission Systems–SDH Equipment–Radio Systems
•STM-1 capacity at various frequencies•Ring closure in regional/local network
Digital Switches
Cross-Connects
Nortel Elements - Network Deployment
Nortel TN-1CProvides state-of-the-art add/drop multiplexer
(ADM) capabilities at STM-1
Can accommodate up to 32 2Mbps G.703 ports (75 and 120 ohm) and/or two 34 Mbps or 45 Mbps ports (ATM ready)
It can be deployed in exchange environments, street cabinets, or at large customer sites
Can be configured as SDH protection ring, chain as well as a terminal multiplexer
Equipped with 10/100 BaseT Ethernet connection
Nortel TN-1X
An STM-1 add/drop multiplexer that provides high-reliability, high-flexibility service transport and management in an SDH metro network
Can be deployed in a number of terminal, add/drop and hub configurations to flexibly suit different network deployment scenarios such as point-point, line, chains and rings
Nortel TN-1X
Provides flexible access to an STM-1 transport aggregate at VC-12 and VC-3 granularity - delivering a high density of 2, 34, 45 and 155 Mbit/s service interfaces, typically at smaller POP locations
Nortel OPTera Metro Family
Nortel OpTera Metro 4000 Series The OPTera Metro 4100 and 4200 Multiservice
Platforms comprise a family of full access STM-4/16 SDH multiplexers
DWDM aggregates can be used to further extend capacity to 10 Gbit/s
Key attributes are small footprint, full access, mixed payload, virtual concatenation and a fully non-blocking 4/3/1 cross-connect functionality
In-service upgrade is available across the OPTera Metro 4000 family
Nortel OpTera Metro 4000 Series
Key Features Accommodates more traffic in fewer shelves and racks
Results in up to 30% floor space savings because of its architecture and high port density
Supports native rate data interfaces
Support for fast Ethernet interface with virtual concatenation
A single shelf can subtend and close multiple protected STM-n rings/spurs and perform fully non blocking VC-12 cross connection for unrestricted bandwidth management
Provides tributary access to full STM-4 and STM-16 protected payload and flexible aggregation for narrow and broadband services
Supports full remote downloads for upgrading thousands of network elements from a single centralized location
OPTera Metro 4100/4200
Key Benefits–Multi service–Lower operating costs–Less staff training–Space saving–Simpler network management–Lower spares holding
Applications
OPTera Metro 4100/4200 is an STM-4 (622 Mbit/s)/STM-16 (2.5 Gbit/s) Full Access high port density multiplexer which can be configured as:–Terminal Multiplexer–Add/Drop Multiplexer–Small cross-connect–Hub Multiplexer–Regenerator
DeploymentOPTera Metro 4100/4200 can be deployed at
the network core, hub and edge with complete service flexibility
The OPTera Metro 4000 series has DWDM capabilities and in addition seamless interoperability with other optical services platform
This ensures flexibility and a scalable evolution path to increase capacity as further wavelengths are added
General Safety Guidelines
Hazardous Materials
Optical Safety Aspects
Class 3A Requirements
Design FeaturesNormal Operating Conditions
– Under normal operating conditions each optical fiber section is essentially a closed system permitting no human access to optical radiation
Installation & System Maintenance– There is no requirement during installation or maintenance for an
operator to view a fiber end or connector while the associated laser is powered
Servicing– The optical units are not intended for servicing by the user. In the
event of a fault, the optical units must be returned to Nortel Limited for repair or replacement
System Operating Levels
Laser output powers are set up and controlled within 0.5 dB of nominal during manufacture
The optical output power level above is the mean power value which is the most onerous from the safety point of view
Identification
SSD Handling Precautions
Nortel TN-1C
The Nortel TN-1C is a STM1 Add/ Drop Multiplexer. Can be Used as ADM/ TM /REG.
• Traffic from 2Mbit/s, 34/45 Mbit/s, can be mapped into the Aggregate STM1 signal
• Aggregate Module : Two STM1 Optical Ports Integrated in One module
• Tributary Port : E1, E3/DS3 and 10 base T LAN/WAN card
System Over View
TN1C
TN1X
OM4100/4200
System Over View
Application View :
1. Flattened Ring -- By using STM1o trib module
2. Ring - TN1Cring by using STM1o trib
1
2
Plug-in tributary cards
Station Interface Area (SIA) housingTraffic Interface Modules (TIM)
System Over View
System Over View
System Over View
•STM-1 aggregate ports— One STM-1 optical card with two aggregate ports
-- Long Reach-- Short Reach
Aggregates Available
System Over View
Tributaries Possible :• 2048 kbit/s electrical ports— up to twenty four 2048 kbit/s electrical ports
• 34368 kbit/s or 45736 kbit/s electrical ports— up to two 34368 kbit/s or 45736 kbit/s ports. Only three of these can carry traffic at any time.
• 10 BaseT LAN/WAN Module— One LAN /WAN Card
Documentation Overview Slide 1/3
The documents are divided into functionally related groups as follows:
• Common provides information common to all TN-1C/TN1P
documents, for example: safety, master index, terms and abbreviations
• Descriptive provides descriptions of the equipment, alarms,
surveillance features, system applications and performance specifications
Documentation Overview Slide 2/3
• Installation provides installation procedures
• Commissioning and testing provides commissioning and software
provisioning information to enable the system to be initialized before services are enabled
• Operations, administration and provisioning provides information needed for OA&P purposes,
this includes Craft Access Terminal (CAT) user procedures
Documentation Overview Slide 3/3
• Maintenance contains information for maintenance
purposes, including procedures for troubleshooting, clearing alarms and replacing units
Documentation ViewTN1C Documentation Suite
System Configuration
System Configuration
System Configuration
Equipment Description
By Functionality TN1C can be divided into Following Areas:
• Traffic processing
• Equipment management
• Synchronization
• Power
• Connectivity
• Protection
• Performance monitoring
• Diagnostics
Equipment Description
Equipment Description
Equipment Description
Equipment Description
Equipment Description
Equipment Description
Power Supply Description
Operating parameters:
Power requirementThe unit can operate from an input voltage in the range 20 V to 72 V d.c.,with either the positive or negative input earthed, without the need to change internal straps.
Maximum total output power 32 W
Unit Description : STM 1 Optical Aggregate
Unit Description : STM 1 Optical Aggregate
Unit Description : STM 1 Optical Aggregate
• If either or both multiplexers detect an RS-LOS indication present for at least 550 ± 50 ms, its laser is shutdown. If the RS-LOS alarm clears (for atleast 100 ± 20 ms), the laser is switched back on immediately.
• If either or both multiplexers detect an OS-Optical_Power_High alarm its laser is shutdown immediately. The laser can not be restarted until the unit is reset (e.g. removed and replaced in the subrack).
Unit Description : STM 1 Optical Aggregate
Unit Description : STM 1 Optical Aggregate
Unit Description : STM 1 Optical Aggregate
A remote (‘far-end’ or ‘loop to line’) loopback can be performed on a selected STM-1 link, i.e. the incoming (from the optics) STM-1 data is routed back to the optical connections on the same link, as well as being transmitted towards the line. While an STM-1 remote loopback is in operation, an RS-Loopback_On alarm is raised.
1X – System Overview
TN – 1X Network ElementVersions
– Full-height version (TN-1X) – Reduced-height version (TN-1X/S)
Tributaries
Aggregates
External Interfaces [1X | 1X/S]
Application Software
User Interfaces
Tributaries2048 kbit/s electrical ports
– Up to sixty-three 2048 kbit/s electrical ports (TN-1X)– Up to sixteen 2048 kbit/s electrical ports (TN-1X/S)
34368 kbit/s or 45736 kbit/s electrical ports– Up to four 34368 kbit/s or 45736 kbit/s ports (TN-1X) (only three
carrying traffic)
34368 kbit/s electrical ports (16x2)– Up to four 34368 kbit/s electrical ports (TN-1X), each port providing
access to sixteen 2048 kbit/s signals
STM-1 tributary ports– Up to four STM-1 optical or electrical tributary ports (TN-1X)– Up to four STM-1 optical tributary ports (TN-1X/S)
AggregatesIt is possible to mix the following aggregate
ports up to a maximum of two:
STM-1 aggregate port– One or two STM-1 optical or electrical aggregate ports
(TN-1X)– One or two STM-1 optical aggregate ports (TN-1X/S)
STM-4 aggregate ports– One or two STM-4 optical aggregate ports (TN-1X and
TN-1X/S)– A Multiplexer fitted with two STM-4 ports is referred to as
TN-1X/4.
External Interfaces – 1X
External Interfaces – 1X/S
Application Software
The TN-1X is managed using embedded application software which performs the internal control and monitoring functions
The configuration and status information is stored in each Network Element (NE) and not in the management tools used to control them
User InterfaceTN-1X monitoring and configuration through UI of the
application software
Accessed through:– Locally by a Craft Access Terminal (CAT) connected directly to the TN-
1X– Remotely via the Preside EC-1 Element Controller
The TN-1X also provides an interface to the rack alarm system (not applicable to the TN-1X/S)
– Browser User Interface (Browser)• Point-and-click hypertext interface. The interface is viewed by Netscape Navigator
– Command Line User Interface• Text-based interface
TN 1X DeploymentWhen used in a managed network environment, the TN-
1X Multiplexer operates as either:
A ‘gateway network element’ (TN-1X only) which provides an interface to the next layer of the network management hierarchy (for example, element controller) and an interface for remote multiplexers via the Embedded Control Channel (ECC)
A ‘network element’ (TN-1X and TN-1X/S) which provides an interface to the next layer of the network management hierarchy, or interfaces via the ECC and a ‘gateway network element’
Preside EC-1 Element ControllerA complete network management application software
package, operating at the Element Manager level of the network management hierarchy
The GUI system can be run on a single HP UNIX workstation to provide flexible management of TN-1X, TN-1X/S, TN-1C, TN-1P and Optera Metro 4100 multiplexers
The Element Controller facilities are divided into five main areas:– Configuration– Alarm/Event Monitoring– Performance Monitoring– Security Management– Reporting
Configuration
This function provides the means of adding, copying, modifying, and removing network elements
The Element Controller provides GUI sessions for configuration and connection management, and also provides access to the UI on the NE for further configuration facilities
Alarm/Event Monitoring
Events (changes in status of network entities) and alarms (indications of actual or potential failures) are received as unsolicited reports from the network element
The Element Controller provides on-screen displays at three different levels of detail (including an Alarm Count only mode), and full event logging and reporting facilities
Performance Monitoring
The TN-1X, TN-1X/S, TN-1C, TN-1P and Optera Metro 4100 NEs have comprehensive performance monitoring facilities, allowing the monitoring of selected points within the multiplexer against a range of performance criteria
The Element Controller uses these facilities to provide powerful report generation features
Security Management
The Element Controller provides security safeguards against unauthorized users, and restricts authorized users to a subset of features appropriate to their role
Data security is provided by automatic daily back-ups of all network data and clear warnings are provided if the system disk becomes too full
Reporting
The reporting function of the Element Controller allows the generation of reports about event logs, performance logs, NE configuration, and faulty equipment
1X – System Description
Construction
TN-1X Subrack variants :– 25G MU00 750 GWV PCS Level 5 - Figure– 25G MU00 750 GWV PCS Level 6 - Figure
TN-1X backplane variants :– 25G MU00 750 HHX PCS Level 5 - Figure– 25G MU00 750 HHX PCS Level 6 - Figure
Equipment Description
TN-1X Block Diagram
TN –1X Subrack Layout
TN –1X Subrack Layout
Plug-In Units Slide 1/2
Power Unit– 1 or 2 units which fit into subrack positions S12 and S13– The Power Units provide the regulated d.c. outputs for the
other units in the subrack– When two Power Units are fitted, they operate as a load
sharing pair– If one of the units fails, the other unit can supply the total
power requirement
Subrack Controller– 1 unit which fits into subrack position S14– The Subrack Controller performs general control and
monitoring functions
Plug-In Units Slide 2/2
Payload Manager– 1 or 2 units which fit into subrack positions S5 and S8– Provides drop and insert facility – Provides reordering facility at the TU level of the SDH – TU-3 operation is only possible when using a mixed
payload Payload Manager (NTKD10AA)– When two units are fitted they operate in a main/standby
configuration to provide protection against a Payload Manager or backplane failure
– In normal operation, both units are active but the outputs of the standby unit are disabled
Plug-In Units Slide 2/2
EOW Unit
1 unit which fits into subrack position S1
Two versions of the EOW Unit are available as follows:– The EOW Unit 25U SV00 750 GVX– The EOW Unit NTKD13AA
EOW Unit (25U SV00 750 GVX
Known as ICC1, provides internal telephone communication between TN-1Xs in a network
Interfaces with a standard DTMF telephone– Provides the analogue/PCM coding/decoding using A-law
companding
The 64 kbit/s PCM data is transferred via the backplane overhead bus to the aggregate units for transmission via the E1 or E2 bytes in the SOH
EOW Unit NTKD13AA
Known as ICC2, provides all the EOW facilities provided by the 25U SV00 750 GVX variant
The unit also is used to control 1:N protection of 2 Mbit/s Tributary Units
Tributary Units The TN-1X and TN-X/S subracks provide six
general purpose tributary unit positions (maximum of five used on TN-1X, maximum of four used on TN-1X/S)
1. 2 Mbit/s Tributary Unit, 75 or 120 – Each 2 Mbit/s Tributary Unit provides sixteen 2048 kbit/s
interfaces– The unit performs the mapping of the tributary into a VC-12
and generates the TU pointer, thus producing a TU-12– The unit performs the corresponding pointer processing and
demapping in the opposite direction
Tributary Units
2. STM-1 Tributary Unit (o or e) – Each STM-1 Tributary Unit provides an STM-1 tributary
port with access to a maximum of sixty-three VC-12 channels or three VC-3 channels (or a combination of the two)
– The unit performs the STM-1 section overhead processing, the TU reordering, and the electrical/optical conversions
• (Note 1: The TN-1X/S does not support STM-1 Electrical Tributary Units.
• Note 2: VC-3 operation is only possible using the mixed payload STM-1Tributary Units (NTKD11AA and NTKD12AA)
Tributary Units
3. 34 Mbit/s Tributary Unit (16x2), 75 – Each 34 Mbit/s Tributary Unit provides a 34368 kbit/s
interface– Performs demultiplexing of the 34368 kbit/s signal into
sixteen 2048 kbit/s plesiochronous channels– Performs the mapping of each channel into a VC-12 and
generates the TU pointer, thus producing a TU-12– Performs corresponding pointer processing, demapping,
and multiplexing in the opposite direction• Note: The TN-1X/S does not support 34 Mbit/s Tributary Units.
Tributary Units
4. 34/45 Mbit/s Tributary Unit (VC3), 75 – Provides a 34368 kbit/s or 44736 kbit/s interface,
conforming to ITU-T recommendation G.703– Performs the mapping of the tributary into a VC-3 of the
SDH and generates the TU pointer, thus producing a TU-3– Performs the corresponding pointer processing and
demapping in the opposite direction
Note: The TN-1X/S does not support 34/45 Mbit/s Tributary Units
STM-1 Aggregate Unit (o/e)
Performs the STM-1 SOH processing and the electrical/optical conversions (STM-1 Optical Aggregate Unit) or the CMI line coding/decoding (STM-1 Electrical Aggregate Unit)
Note: The TN-1X/S does not support STM-1 Electrical Aggregate Units.
STM-4 Optical Aggregate Unit
The STM-4 Optical Aggregate Unit performs :– STM-4 electrical/optical conversions– STM-4 SOH processing – Dropping/Insertion of one of the AUGs within the STM-4
signal
TN-1X – Tributary Options– 2 Mbit/s Tributary Unit, 75 or 120 (up to 4
units)– or– STM-1 Optical or Electrical Tributary Unit (up to
4 units)– or– 34/45 Mbit/s Tributary Unit (VC-3) (up to 4 units)– or– 34 Mbit/s Tributary Unit (16x2) (up to 4 units)– Subrack positions S2, S4, S9 & S11
TN-1X – Tributary Options - 2
Occupies two slots and can only be fitted in positions S2 and S9 (i.e. unit in position S2 occupies slots S2 and S3, unit in position S9 occupies slots S9 and S10)
For 1:N protection, a 2 Mbit/s Tributary Unit is fitted in Subrack position S3
TN-1X – Aggregate Options
STM-1 Optical or Electrical Aggregate Unit (up to 2 units) or
STM-4 Optical Aggregate Unit, 1310 nm or 1550 nm (up to 2 units) or
1STM-1 Aggregate Unit & 1 STM-4 Aggregate Unit
Subrack positions S6 and S7
Interface Modules
Provide the external electrical connections
Two Types
1. Traffic Interface Modules (TIMs)– Provide the traffic connectors.
2. Service Interface Modules (SIMs)– Provide the general rack connectors
Nortel TN-1X System DescriptionSIMs and TIMs :
– 75Traffic Access Module• Provides connections for eight 2 Mbit/s 75 tributary ports• Two modules are required for the full 16 channels of a 2 Mbit/s Tributary Unit
– 75Traffic Access Module 1:N Protection• Provides connections for eight 2 Mbit/s 75 tributary ports• Contains the relays used to switch traffic when 1:N protection is employed• Two modules are required for the full 16 channels of a 2 Mbit/s Tributary Unit
– 120Traffic Access Module• Provides connections for eight 2 Mbit/s 120 tributary ports• Two modules required for the full 16 channels of a 2 Mbit/s Tributary Unit
– 120Traffic Access Module 1:N Protection• Provides connections for eight 2 Mbit/s 120 tributary ports• Contains the relays used to switch traffic when 1:N protection is employed• Two modules are required for the full 16 channels of a 2 Mbit/s Tributary Unit
System Description contd.
SIMs and TIMs :– High Speed Traffic Access Module (16x2)
• Provides connections for a 34 Mbit/s 75 tributary port
– High Speed Traffic Access Module (VC-3)• Provides connections for a 34 Mbit/s or 45 Mbit/s 75 tributary port
– 1:1 Manual Tributary Protection Traffic Access Module (VC-3)• Provides no connections, but receives traffic from a High Speed Traffic Access Module (VC-3) via the Star Card
– High Speed Aggregate Module• Provides connections for a STM-1 electrical aggregate port
– High Speed Tributary Module• Provides connections for a STM-1 electrical tributary port
– Station Service Module• Provides connections for the rack alarm bus, the management Q3 port (LAN)
System Description contd.
SIMs and TIMs :– 75Star Card
•The 75 Star Card provides connections for the external synchronization timing ports
– Flexible Access Module•Provides the connections to the LCAP
Connector PanelsLocated at the front of the Station Interface Area
75Connector Panel– Provides SMB connections for sixteen 2 Mbit/s 75 tributary ports.
120Connector Panel– Provides four 25-way D-type connections for sixteen 2 Mbit/s
120 tributary ports
EOW/CATT Connector Panel– Provides access to the Subrack alarm facilities (alarm LEDs,
receiving attention push-button switch), local terminal and EOW connectors
Local Craft Access Panel (LCAP)Mounted centrally on the front of TN-1X Subrack
Provides interfaces commonly used by installation and maintenance engineers as well as Subrack alarm facilities
Right-hand side of the panel contains the subrack alarm facilities (alarm LEDs, receiving attention push-button switch), and an ESD bonding point
Hinged face plate cover provides access to the commonly used connectors
Interface with the Subrack Controller via the SIM in position T1
1X – System Configuration
System Configurations
Conventional Terminal Multiplexer in protected point-to-point configurations
Drop and Insert Multiplexer with two aggregate units
Terminal Multiplexer with a single aggregate unit–Unprotected point-to-point connections–End terminals in DI Chain
Typical System Configuration
Terminal MultiplexerAs a conventional terminal multiplexer with 2 aggregate
units, TN-1X provides a p-p link with inherent 1-1 protection
Achieved by configuring the mux as a D&I multiplexer and:
– Configuring the aggregates for MSP or – Setting all tributaries as protected connections
An unprotected terminal multiplexer configuration can be achieved by :
– Configuring the 1X as a D&I mux– Setting all tributaries as unprotected connections to 1 aggregate port– Unequipping the unused aggregate port
Terminal Multiplexer View
Drop & Insert Multiplexer Slide 1/2
When configured as a D&I mux (Add/Drop Multiplexer - ADM), TN-1X can be used in two configurations:– Drop and insert chain – Figure Figure – Drop and insert ring – Figure
As a simple D&I chain , no protection is provided against faults in the optical path and the mux are configured as unprotected– The end terminals only require a single aggregate port
Drop & Insert Multiplexer Slide 2/2
Flattened rings – Figure b make use of existing patterns of ducts and fibers to form a distorted ring
Protection against faults in the optical paths is provided by routing the traffic simultaneously both ways around the ring and configuring the mux as D&I mux
However, the flattened ring configuration is susceptible to the common mode faults (e.g.both optical fibers in a duct being broken at the same time)
Drop & Insert Multiplexer View
Drop & Insert Multiplexer RingThe D&I ring provides diverse routing which
overcomes common mode faults and thus provides protection against a fault in any optical path
Tributaries that require protection are routed both ways around the ring
At the receiving mux, traffic from one aggregate port is used unless there is a fault when traffic from the other aggregate port is used
Drop & Insert Multiplexer Ring View
STM-4 AggregatesWhen STM-4 Aggregate Units are used, each TN-1X/4
multiplexer is used to :– Provide D&I facilities for any one of the 4 AUGs which make up the
STM-4 payload– The remaining three AUGs are routed from aggregate unit A to aggregate
unit B, and vice-versa, for onward transmission – In this way, the payload in the ‘East’ and ‘West’ directions (Figure ) is
maintained.
The TN-1X/4 can also be used to provide the grooming function at the ring head
– Requires access to 1,2,3 or 4 AUGs within the STM-4 aggregate signal – Requires a separate TN-1X/4 multiplexer for each AUG to be accessed
ApplicationThe main application of the TN-1X/4 multiplexer is in
optical rings where it is used to provide access to both private and switched traffic as follows:
– Private Circuit (PC) traffic is routed to • Other access rings terminating at the same ring head site or
• Alternatively to other remotely sited access rings
– Switched traffic is routed to the Digital Local Exchange (DLE)– Whilst most of the traffic flow will be from ring node to ring head, some
private circuit traffic will be routed between:• Ring nodes
• Some switched traffic will be routed between remote switches attached to the ring nodes
STM –1 Routing
1X/4 - STM-4 Access Ring Deployment
STM-1 Tributaries
The TN-1X provides STM-1 tributaries– For the connection of partially filled STM-1 spurs – Inter-ring connectivity
Examples of STM-1 tributary applications :– STM Spur – Unprotected– STM Spur – Protected– Interconnection of STM rings – Unprotected– Interconnection of STM rings – Protected– Interconnection of 1X/4 using different AU4s in STM ring
STM Spur – Unprotected
STM Spur – Unprotected
Figure shows the connection of a STM-1 spur from a TN-1X (typically a TN-1X/S situated at the customer premises or in street cabinets) to a TN-1X STM-1 ring
In this application, the TN-1X at the customer premises is configured as an unprotected terminal multiplexer – Connected to a STM-1 Tributary Unit at the TN-1X in the
STM-1 ring– No protection is provided for traffic on the spur
STM Spur – Protected
STM Spur – ProtectedFigure shows the connection of partially filled STM-1
spur from a TN-1X to a TN-1X/4 STM-4 ring using duplicated STM-1 tributaries
In this configuration, Multiplex Section Protection (MSP) is used to provide protection for the spur traffic
– The spur TN-1X is configured as a protected terminal mux with the aggregate ports configured for MSP
The STM-1 tributaries at the TN-1X/4 in the STM-4 ring must also be configured for MSP
In the event of failure of the working path, traffic is automatically switched to the protection path
STM Rings Interconnection– Unprotected
STM Rings Interconnection – Unprotected
Figure shows the interconnection between a TN-1X STM-1 ring and a TN-1X STM-4 ring
In this application, both TN-1Xs are configured as drop and insert multiplexers
No protection is provided for traffic on the spur
STM Rings Interconnection– Protected
STM Rings Interconnection–Protected
Figure shows the interconnection between two TN-1X STM-1 rings using duplicated STM-1 tributaries
In this application, both TN-1Xs are configured as D&I mux with each pair of STM-1 tributaries configured for MSP to provide protection for the inter-connection traffic
In the event of failure of the working path, traffic is automatically switched to the protection path
Interconnection of 1X/4 (STM ring)
Interconnection of 1X/4 (STM ring)
Figure shows the interconnection between TN-1X/4s in an STM-4 ring– Which are dropping/inserting different AU4s, allowing for
traffic grooming between AU4s in the ring
Single Fiber WorkingThe TN-1X is capable of operating in a single fiber mode
– A single optical fiber is used to carry bi-directional optical signals between adjacent mux
– The conversion between two fiber working and single fiber working is performed externally to the multiplexer by a 2-1 optical converter box (Figure )
– If a break occurs in the single fiber, there is a possibility of the transmitted traffic being echoed by the 2-1 optical converter box to the receive port on the same multiplexer
– This signal must be recognized as faulty and Alarm Indication Signal (AIS) transmitted downstream
– To recognize the echoed signal, the high-order path trace facility should be used with the transmit and receive path trace settings set to different values and the consequent actions enabled
Single Fiber Working
Single Fiber WorkingIn the event of a broken fiber where the echo is sufficient
to constitute a valid signal:– The multiplexer does not behave in the normal manner to a Loss of Signal
event– A transient Loss of Frame alarm will be raised whilst the mux is
achieving frame alignment to the echoed signal
The Loss of Signal alarm is used as a trigger for automatic laser shutdown (ALS)
In the event of a broken fiber (sufficient echo) the Loss of Signal will not be raised
– Therefore ALS is not supported when operating in a single fiber mode
Engineering Order Wire Slide 1/3
Provides a dedicated telephone communication system
For maintenance purposes between TN-1Xs in a ring or line configuration
The facility only operates over a single ring or chain and does not support branches or multiple rings/chains
A maximum of 99 nodes are allowed in the ring or chain
Uses the E1 or E2 bytes (hardware selectable) in the STM section overhead to provide a 64 kbit/s voice communication channel between TN-1Xs
Engineering Order Wire Slide 2/3
If the path section is invalid (i.e. out of alignment), the communication path is disconnected
Both ends of a path segment needs to be set to use the same EOW byte
The EOW system requires a single EOW Unit at each TN-1X in the network
The EOW system uses a standard DTMF telephone which is connected to :
– The Local Craft Access Panel on the TN-1X– The EOW/CATT Connector Panel on the TN-1X/S
Engineering Order Wire Slide 3/3
TN-1X Connection Types
TN 1X – Power Units
1X Power Units Slide 1/2
Contains one or two Power Units which provide the +5 V, –5.2 V, +12 V, and –2 V supplies for the subrack units
The Power Units operate in a load sharing mode, however, each Power Unit is capable of supplying the total power requirement
Removal/Insertion of power units possible in load sharing mode without affecting the performance of TN-1X
The Power Units operate from a battery supply in the range of 40 V to 72 V (nominal 48 V or 60 V)
Each subrack requires two separately fused supplies
1X Power Units Slide 2/2
One supply is used to provide the ‘power’ input to the first Power Unit and the ‘alarm’ input to the second Power Unit
The other supply is used to provide the ‘power’ input to the second Power Unit and the ‘alarm’ input to the first Power Unit
This ensures that power is still available to the subrack if one of the fused supplies fails
1X Power Units – Block Diagram
Protection
VC-12/VC-3 Path Protection Switching
The Subrack Controller can provide autonomous PPS at the VC-12 and VC-3 levels
– Protection of the VC-12s and VC-3s is performed by:– Transmitting the VCs from both aggregate ports– Performing autonomous protection switching between the received VCs
at the terminating mux
Protected VCs occupy the same logical channel at both aggregate ports
Unprotected VCs only occupy a logical channel at one aggregate port, allowing the same logical channel at the other aggregate unit to be used for another unprotected VC
VC-12/VC-3 Path Protection Switching
In case of an optical fault ALS is initiated – Causes traffic in both directions of the ring section to be
shut down – Results in a dual ended path switch that sustains traffic
during an optical fault in one section of the ring
Modes of Operation
2 Modes – UI Selectable
Automatic
Manual
Automatic PPS
In the automatic mode (PPS on), a path protection switch will occur if any of the following alarms exist on the Payload Manager, 2 Mbit/s Trib Unit, 34 Mbit/s Trib Unit (16x2) or 34/45 Mbit/s Tributary Unit (VC-3):
INT-AU-AIS
Internal-Administrative-Alarm Indication Signal
INT-AU-LOP (Loss of Pointer)
HP-LOM (Loss of Multiframe)
TU-AIS
TU-LOP
Note - 1The HP alarms cause a protection switch on all the
protected VC-12 and VC-3 paths
The LP alarms cause a protection switch on the specific VC-12 or VC-3 path against which the specific alarm was raised
A protection switch will also occur on all protected VC-12 and VC-3 paths as an indirect consequence a RS-LOS, RS-LOF, MS-AIS, MS-EXC and HP-TIM alarms raised on an Aggregate Unit (due to AU-AIS being injected towards the Payload Manager)
Note - 2
PPS is controlled by the user interface and is enabled/ disabled for each path separately
Automatic PPS is disabled for 2 minutes after changing the on-line configuration
If a condition which should trigger protection switching occurs during the two minutes, switching will be delayed until the end of the 2 minute period
Manual PPS
In the manual mode (PPS off), a path protection switch can be initiated on each path individually via the user interface
It is not possible to perform a manual switch while the mux is in detached mode
Persistence Checks
Failure Persistence Check–Overcome undesired protection switches– In case of higher levels (VC-12 thru STM –16)
Restoration Persistence Check– Prevent the a protection switch to a faulty path and
excessive oscillations between paths due to LP-EXC alarms being raised on both paths
STM-1 Tributaries Protection
TU-AIS – Main mechanism to trigger automatic PPS–Applicable for 25U TM00 750 HWG, 25U TM00 750
JBK, NTKD11AA, NTKD12AA, NTKD11AB and NTKD11BA
LP-EXC alarm acts as the trigger mechanism–Applicable for 25U JU00 750 GVA/GVB and 25U
TM00 750 HWE
1:N 2 Mbit/s Trib Protection1:N trib protection allows traffic on any of the 2 Mbit/s
Trib Units to be switched to a protection 2 Mbit/s Trib Unit in the low-speed trib protection slot (S3)
For 1:N protection to be used, the following units/modules must be fitted:
– 2 Mbit/s Trib Units in the normal (S2, S4, S9, and S11) and protection (S3) slots must be of the same impedance type (75 or120 )
– The protection 2 Mbit/s Trib Unit in slot S3 must be equipped as either HVT or HVQ
– 1:N Protection 2 Mbit/s Traffic Access Modules (TAMs) must be fitted – Each 2 Mbit/s Tributary Unit, except the protection 2 Mbit/s Unit,
requires two 1:N Protection TAM– The EOW Unit (ICC2) (NTKD13AA) must be equipped
Precautions
Modes of Operation
Disabled
Automatic
Auto – Revertive
Manual
Disabled
When 1:N tributary protection is disabled, no protection of the 2 Mbit/s Trib Unit is provided, even though the necessary units may be equipped
Automatic Mode
In the automatic mode, 1:N protection switching is controlled by the mux
An automatic 1:N protection switch will occur if any of the following alarm conditions exist on a 2 Mbit/s Trib Unit in slot S2, S4, S9 or S11:– NE-Card_Out– NE-Card_Fail– NE-Card_Fault
Automatic Mode contd.
NE-Card_Out - 1:N protection switch occurs– Traffic is routed through the protection card and full traffic will be
restored
NE-Card_Fail and NE-Card_Fault can take seconds to detect
After an automatic switch has occurred, no more automatic switches are possible as the protection 2 Mbit/s Trib Unit is being used to carry traffic
If the working card recovers, traffic remains permanently on the protection card, unless the user performs a manual reversion
Auto – Revertive
Enables protection traffic to return automatically to the working card when the switching condition clears
Occurs a specified time after the condition has cleared - Wait-To-Restore (WTR) period (300 seconds)
The WTR period applies to the protection card
Note: Not supported on the Preside
Manual
In the manual mode, the protection switch is initiated by the user via the user interface
It is not possible to perform a manual switch while the mux is in detached mode
Switching PrerequisitesThe EOW Unit (ICC2), the active Payload
Manager and the protection 2 Mbit/s Trib Unit (S3) do not have any NE_Card_Fail
NE_Card_Out, or NE-Card_Fault alarms present
The faulty 2 Mbit/s Trib Unit must have traffic connections made
1:N protection switch has not already been made, i.e. the protection 2 Mbit/s Trib Unit (S3) does not have traffic connections
1:N Trib Switching AlarmsNE-np1_switch_Alarm
– Indicates that a successful manual or automatic switch to the protection 2 Mbit/s Trib Unit has occurred and the other 2 Mbit/s Trib Units are no longer protected
– The alarm will be cleared when a manual reversion to the original 2 Mbit/s Trib Unit is performed
NE-Card_Out (for TAM slot)– This alarm indicates that an 1:N Protection 2 Mbit/s TAM has been
removed from the subrack.
NE-Wrong_Card (for TAM slot)– Indicates that a wrong TAM has fitted or the 1:N Protection TAM has
failed
Payload Manager Switching
Payload Manager SwitchingThe Payload Managers operate in a main/standby mode
with only the traffic outputs of one Payload Manager active at any one time
If the Subrack Controller detects a fault on the main Payload Manager, it instructs the standby Payload Manager to become active (if no faults are present on the standby Payload Manager)
The Subrack Controller also instructs the relevant trib and aggregate units to receive/transmit via the standby Payload Manager
Payload Manager (B) is the default main unit
Operation Modes
Automatic– Payload Manager switching is controlled by the Subrack
Controller and will occur if any of the following alarm conditions exist on the active Payload Manager:•NE-Card_Out
•NE-Card_Fail
•NE-Card_Fault
•INT-NE-Comms_Fail
•INT-SYNC-Oscillator_Fail
•HP-LOM
Operation Modes
Manual– In the manual mode, the protection switch is initiated by the
user via the user interface– It is not possible to perform a manual switch while the mux
is in detached mode
Switching PrerequisitesThe standby Payload Manager is equipped and does not
have any of the Payload Manager switching conditions
If the Payload Manager switching is automatic, the standby Payload Manager must be the same variant as the active Payload Manager
If the Payload Manager switching is manual, no VC-3 connections must be present if switching from a mixed payload Payload Manager to a non-mixed payload Payload Manager
Multiplexer Section Protection 1/6 Multiplexer section protection (MSP) is a
mechanism that enables protection switching for all traffic on an STM-1 channel
A 1+1 protection architecture is supported, which uses a second STM-1 channel of the same type
This protection channel carries the same traffic as the original working channel
MSP controls which of these channels is used as the current channel
MSP Slide 2/6
MSP monitors both STM-1 channels for failures
The protection status of the link is carried in the K1 and K2 bytes within the mux SOH of the protection channel
The MSP mechanisms on the local mux and the remote mux transmit protection status information using these bytes
This enables the mechanisms to determine which of the channels should be used,and to perform a protection switch as appropriate
MSP Slide 3/6
MSP will switch to the protection channel under a number of alarm and non-alarm conditions
To revert to using the working channel, a manual switch must be used. Automatic reversion is not supported
The MSP mechanism can be locked to prevent the use of the protection section
It is also possible to force the mechanism to use either the working channel or the protection channel, and to test the working channel for errors
MSP Slide 4/6
When MSP is established, the protection channel must have no connections present
There is a command that converts protected connections to unprotected connections on aggregates that are to be used for MSP
MSP cannot be established on an STM-1 tributary unit that has trib-to-trib connections
MSP Slide 5/6
Once MSP is established, the protection channel is inaccessible to the user,but its configuration mirrors that of the working channel at all times
All references in events, logs and reports to MSP channels refer to the working channel, even after a protection switch
MSP Slide 6/6
Protected drop connections are supported when a pair of STM-1 trib channels are used for MSP
Protected drop connections are not supported when both STM-1 aggregates are used for MSP
MSP supports both unidirectional and bi-directional modes of operation
MSP Configurations
ExampleMSP protection between two rings - Figure
The two rings are connected via an STM-1 tributary channel (Link X)
A second tributary channel that carries identical traffic (Link Y) provides 1+1 MSP protection
If Link X fails, an MSP switch occurs
The protected and unprotected traffic that was received at either end of the protected channel from Link X is received instead from Link Y
MSP Ring
Unidirectional OperationIn unidirectional mode, traffic moves in both
directions, but the MSP mechanisms operate independently
The switching is evaluated at the receive end only
When a switch occurs, only the failed direction is switched from the working channel to the protection channel
Override values for the K1 and K2 bytes can be used for unidirectional operation
Unidirectional Operation
Bi-directional OperationDefault setting
Traffic moves in both directions– MSP mechanisms communicate and coordinate the switching of both
channels as a pair
When a switch occurs, the use of both channels is switched from the working channel to the protection channel
Switching of a single direction is not supported in this mode
Override values for the K1 and K2 bytes are not used during bi-directional operation
PrecautionsFor bi-directional mode to be active, both local and
remote NEs must be configured to use bi-directional mode
If only one is configured in this way, MSP will not function correctly
Bi-directional operation is implemented in the same way for all MSP configurations
Bi-directional operation is the preferred method when interworking with Nortel Networks TN-16X and SONET equipment
Bi-directional Operation
Switching ConditionsTN-1X supports both manual and automatic MSP
switching
It is not possible to perform a manual switch while the mux is in detached mode
An automatic MSP switch is initiated via the K bytes under the following conditions:
– Equipment failure• Characterized by a Signal Failure (SF) condition, specifically card fail, card fault or card out alarms
• A ‘hard failure’ condition detected on the incoming STM-1 signal
• This is characterized by a signal failure (SF), specifically LOS, LOF, MS-AIS or MS-EXC alarms
MSP Protocol
MSP operates using a bit-oriented protocol that is transmitted in the K bytes (K1 and K2) of the mux SOH of the protection channel
The K bytes indicate the protection status of both working and protection channels, and are used by the MSP mechanisms on the local and remote mux to determine any required switching actions
K1 Byte
K1 byte indicates a request from the mux that generated it:– Bits 1 to 4 indicate the request type
•A condition associated with a failure. For example, Signal Degradation (SD) or Signal Failure (SF)
– This condition can be high or low priority (high by default)
•A state of the MSP function– For example, Wait To Restore (WTR), Do Not Revert (DNR), No Request (NR),
Reverse Request (RR)
•An external request– Lockout of Protection, Forced, Manual or Exercise.
– Bits 5 to 8 indicate the channel for which the request is issued•This indicates either the working or protection channel
K2 Byte
The K2 byte carries status information:– Bits 1 to 4 indicates the channel number being bridged
•This is the number of the channel being carried simultaneously on the standby channel
– Bit 5 indicates whether 1+1 or 1:N architecture is in use.– Note: 1:N architecture is not supported by TN-1X.– Bits 6-8 are mostly reserved for future use, though there are
two values that are used currently– Note: There are a number of binary settings that are not
generated by the TN-1X – Other SDH equipment can generate these settings, however,
and the TN-1X will recognise these
MSAP AlarmsMSP_Prot_Scheme_Mismatch
– This is raised after 50 ms if there is a difference between bit 5 in the sent and received K2 byte
– Indicates that the remote and local MSP mechanisms are configured for different MSP architectures
MSP_Invalid_K_Bytes– This is raised if there is an invalid channel number or an invalid request
indicated in either of the received K bytes for longer than 50 ms– In this instance, if the protection channel is in use, a signal fail condition
on the protection section occurs– As a result, an MSP protection switch from the protection channel to the
working channel occurs
MSAP Alarms
MSP_Channel_Mismatch– This is raised if the K1 transmitted and K2 received channel
numbers are different for longer than 50 ms– In this instance, if the protection channel is in use, a signal
fail condition on the protection section occurs– As a result, an MSP protection switch from the protection
channel to the working channel occurs– This alarm will not be raised if there is a signal fail on the
protection section
Synchronization
Synchronization
SSP functionality of the TN-1X enables a user to control the way in which synchronization is sourced for the mux
TN-1X can synchronize to any external signal traceable to a Primary Reference Clock (PRC) (For
integration into an SDH network)
Synchronization SourcesThe local clock (155,520 kHz) used for synchronizing the
TN-1X provided by the main (active) Payload Manager
The synchronizing clock can be slaved from any of the following sources:
– Tributary Synchronization (TS) backplane signal• Either of the incoming aggregate STM-1 or STM-4 signals, A or B• Any STM-1 tributary signal• Any 2048 kbit/s PDH tributary input on a 2M or 34M (16x2) trib unit• Any 34368 kbit/s PDH tributary input• Any 44736 kbit/s PDH tributary input
– External 2.048 MHz interface (N.A on the TN-1X/S)• Connection is via the Star Card module
– Internal 16.384 MHz master oscillator (with an accuracy of 4.6 ppm) on the Payload Manager
Note
1. If a STM-4 aggregate signal is selected, the signal is derived from the AUG (STM-1) signal being dropped, which is synchronized to the incoming STM-4 signal.
2. Either section of an MSP protection pair can be used for synchronization purposes operating independently
3. Recommended that synchronization is taken from non-PDH sources in preference to PDH sources.
4. Provision for adding unused or unconfigured tributary/aggregate port to the SSH
User responsibility to ensure valid and configured synchronization sources in the hierarchy
Synchronization – Block Diagram
Precautions
1. Loss of active synchronization source can cause loss of all traffic for approximately 200 ms
2. Switch to an alternative synchronization source before replacing a unit or re-provisioning the multiplexer
3. Systems with subracks using STM-4 aggregates should not be run with the synchronization independently set to ‘Internal
They should be synchronized via the line back to a common source
4. Do not apply a ‘Local’ loopback for a tributary selected as the active synchronization source
– Multiplexer Synchronization Loss
Synchronization Source HierarchyBasis for synchronization source protection (SSP)
Formed from four user identified sources
The first source has the highest priority for the user, with the fourth having the lowest
A standby signal is also available, which is always the internal oscillator on the Payload Manager
Only sources listed within this hierarchy are considered for use.
The selected synchronization source is used until the source fails, or a decision to change sources is taken
Typical Synchronization Source Hierarchy
Synchronization Settings Slide 1/4
Use of SSH is controlled by reversion and force settings
Reversion On/Off– Reversion controls the selection of a source if a source fails:– Reversion On
• If a source fails, or a decision to change sources is made,both higher and lower priority sources can be selected for use
• The higher priority source is only considered if that source has recovered
– Reversion Off• When a source fails, or a decision to change sources is made, only sources of a lower priority can be selected for use
• If a source fails, a non-reversion flag is set on this source to prevent its re-selection at a later stage
• This flag must be cleared manually by the user before that source is available for selection again
Synchronization Settings Slide 2/4
Reversion settings are not used when a source is in forced use
Force On/Off– Force On/Off allows the user to manually select the source to be used.– Force On– Using this setting, one of the sources in the hierarchy, including one that
is currently invalid, is selected for use– The TN-1X is not able to change to a different source while in this
mode– If a source becomes invalid while in this mode, or if an invalid source is
selected for use, the TN-1X begins a ‘holdover period’– During this period, the TN-1X reproduces the absent synchronization
signal internally
Synchronization Settings Slide 3/4
– The hold over period is resolved in the following ways:•If the source becomes stable again during this time, the source is used as if had not been interrupted.
– If the holdover period ends (typically after five seconds) without the source becoming available, the standby source (the internal oscillator) is used.
Note 1: When a source is in forced use, reversion settings are ignored.
Note 2: During holdover, a QL =15 is transmitted for Payload Manager variant 25U PJ00 750 GXF and QL = 11 is transmitted for Payload
Synchronization Settings Slide 4/4
– Force Off•Using this setting cancels any existing forced source usage, and source selection comes under the control of reversion setting
•Existing non-reversion flags are unaffected when this mode is selected
•Note: The circumstances under which a switch in synchronization occurs depends on the implementation mechanism used
Synchronization Switching Mechanisms
The circumstances under which a switch in synchronization occurs depends on the implementation mechanism used
There are two mechanisms:– A Synchronization Status Messaging (SSM) mechanism
•This uses transmitted quality levels to determine the best source
– A non-SSM system•This is similar to the synchronization mechanism used
Synchronization Status MessagingSynchronization status messaging (SSM) is based on the
transmission of synchronization quality messages between potential synchronization sources
Mechanism to evaluate best synchronization source
Used under two circumstances:– The best source will always be selected for use, subject to software
settings restrictions – If a better quality source is identified (and no source is in forced use),
the current reversion settings will dictate whether this source can be selected for use
If a source fails, the best of the remaining sources will be selected for use, subject to software settings restrictions
SSM contd.If no source is available, the standby source is selected
Note: SSM mechanism can only select sources that are listed in the synchronization source hierarchy.
The Quality Level (QL) of a source is transmitted in the SOH of all STM-N signals as the S1 byte
QL has a possible range of 1 to 15, with 1 as the highest priority
In practice, a subset of these values is used by the TN-1X - Table
SSM contd.QL transmitted on all STM-N ports, except for the STM-
N port from which it receives its synchronization source
The QL transmitted on this port is 15, which indicates to the source of the synchronization that the TN-1X should not be used for synchronization
This action prevents closed synchronization loops, where two multiplexers each attempt to synchronize from the synchronization signal of the other
SSM – QL Settings
SSM - STM-N ring [Single External Source]
STM-N Ring [Single Ext Clock]
Figure - synchronization is derived from the Primary Reference Clock (PRC)
PRC is the external (EXT) source with a QL=2 at TN-1X(A)
The other TN-1Xs in the ring have their hierarchy set– Derive synchronization from the counter-clockwise TN-1X
in preference to the clockwise TN-1X (that is, on their B ports in preference to A)
STM-N Ring [Single Ext Clock]The QL = 2 clock is transmitted on all STM-N ports for
the TN-1X– with the exception of the return port of the synchronization source, on
which QL = 15 (“do not use for synchronization”) is transmitted– This prevents closed synchronization loops– Note: Before the PRC signal was introduced, all four TN-1Xs would
have used the default QL setting of 11, which indicates the use of an internal oscillator (INT)
If a fiber break occurs, the TN-1Xs after the break will send a QL = 11 in the counter-clockwise direction
The last TN-1X in the ring will switch to the higher quality clock (QL = 2) being sent from the TN-1X with the PRC in the clockwise direction
STM-N Ring [Single Ext Clock]
The QL = 2 clock is then available from its clockwise port, so moving in a clockwise direction around the ring each TN-1X will switch to the PRC QL = 2 clock
The ring will then be synchronized to the highest available quality clock
Simple Ring - 2 Reference Sources
STM-N Ring [2 Ref Clocks] Slide 1/3
Synchronization is derived from the Primary Reference Clock (PRC)
The PRC is the external (EXT) source with a QL=2 at TN-1X(A)
There is also a Secondary Reference Source (SRC) which is also external and has a QL = 3 at TN-1X(B)
The other TN-1Xs in the ring have their hierarchy set to derive synchronization from the counter-clockwise TN-1X in preference to the clockwise TN-1X (B ports in preference to A)
STM-N Ring [2 Ref Clocks] Slide 2/3
The QL = 2 clock is transmitted on all STM-N ports for the TN-1X,
– With the exception of the return port of the synchronization source, on which QL = 15 (‘do not use for synchronization) is transmitted
– This prevents closed synchronization loops.
In the event of a failure of the primary reference source the TN-1X with the primary source switches to an internal clock with a QL = 11
This will propagate around the network until it reaches the TN-1X with the secondary reference source which will switch to the SRC and transmit a QL = 3
STM-N Ring [2 Ref Clocks] Slide 3/3
This will then propagate around the network in a clockwise direction with the other TN-1Xs synchronizing to the secondary reference source
Note: The hierarchy on the TN-1Xs with the external sources are set so that one synchronizes in a clockwise direction around the ring and the other in a counter-clockwise direction
This is to prevent synchronization timing loops
Chain Network - 2 Reference Sources
Chain Network - 2 Reference Sources
For a chain network, there must be two reference sources, one at each end of the network
In normal operation, the chain will derive its synchronization from the primary source
In the event of failure of the PRS, the chain will derive its synchronization from the SRS
In the event of a loss of a link, the chain will divide into two synchronization islands:
– One using the PRS– Other the SRS
Non-SSM Synchronization Sourcing
When the SSM system is not in use, changes to the selected synchronization source only occur when a source fails, or if a manual change is performed
With SSM off, the TN-1X can operate in one of three modes dependent on the reversion and force settings
1. Manual-only selection mode (MANUAL)– In this mode automatic selection of the synchronization source is
disabled– The synchronization source is selected manually by the user– The user can select any available synchronization source, no validity
check is provided on the selected source– This mode is selected by setting force on and SSM off (the reversion
setting has no effect)
Non-SSM Synchronization Sourcing
2. Automatic Switching with Manual Reversion Mode (FALLBACK)
– Mux switches to the next highest priority valid source if the selected synchronization source fails
– If a higher priority synchronization source recovers, it is not automatically selected as the synchronization source
– To switch back to the higher priority source, the user must perform a manual reversion
– This mode is selected by setting reversion off, force off and SSM off
Non-SSM Synchronization Sourcing
3. Automatic switching with automatic reversion mode (REVERSION)
– In this mode the multiplexer switches to the highest priority valid source available
– If a higher priority synchronization source recovers, the source is automatically selected as the synchronization source
– This mode is selected by setting reversion on, force off and SSM off
Synchronization Alarms Slide 1/2
There are five alarms associated with the synchronization facility, namely:
1. SYNC-SETG_Fail Indicates failure of the currently selected source
2. SYNC-Src_Not_Primary Indicates that the primary synchronization source is not currently selected.
3. INT-SYNC-Trib_Line_Fail Indicates that the status of the Trib Sync line is unreliable (that is, activity
is detected when not expected or no activity when expected)– Alarm detected during a synchronization source switch and indicates that
either the unit that was providing the source has not switched it off– or the unit providing the new synchronization source has not switched it on
Synchronization Alarms Slide 2/2
4. INT-SYNC-Oscillator_Fail - indicates that the internal oscillator has failed
5. SYNC-Ext_ Sync_LOS - indicates that the external synchronization source has failed
User Interfaces
CLUI
The Command Line User Interface (CLUI) facilitates access, configuration and control of the network element
CLUI resides between the user and the application software, and is accessed via:– A Craft Access Terminal (CAT)– A Preside EC-1 Element Controller.
Craft Access Terminal (CAT)
An IBM compatible PC running MS Win 3.1 /Win 95/Win 98/Win NT 4.0/Win 2K
Terminal emulation software
Communication with the NE via an RS232-C interface connected to the network element’s CAT interface
Preside EC-1 Element Controller
An HP workstation running the HP-UX 10.20 operating system and the Preside EC-1 Element Controller management software
The Preside EC-1Element Controller communicates with the NE via a Local Area Network(LAN)
User Interface Structure Slide 1/4
The UI is text-based, and is structured as a hierarchical message set.
The UI provides access to the following functionality on the TN-1X NE:– Viewing and reporting on all aspects of NE operations.
•Display of system messages, alarms and events in real time.
•Generation of alarm and event logs.
•Performance monitoring.
•Status of system settings.
User Interface Structure Slide 2/4
UI Functionalities
Diagnostics actions:– Loop backs
Maintenance actions:– Terminating performance monitoring– Setting the Multiplexer clock– Manual VC-12/VC-3 path protection switching.– Manual VC-3 1:1 tributary protection switching.
Configuring the NE:– Card configuration– Connection management– Communications management
User Interface Structure Slide 3/4
Configuring the NE:– Path protection switching– Multiplexer section protection switching– Performance monitoring– Alarms management– External alarms– Synchronization source protection– Consequent actions– Low-order path tracing– High-order path tracing– Low-order payload label definition– High-order payload label definition– Payload manager protection– 1:N Tributary protection– 1:1 manual tributary protection
User Interface Structure Slide 4/4
User interface session management
Software and configuration table management.
User administration
Menu Structure Slide 1/3
The User Interface (UI) for the TN-1X has a text-based hierarchical menu tree
After login a user is positioned at the top level of the menu tree
Example:Config/, View_status/, Session/, Admin/, Maint/,
Diagnostic/, Logout
TN-1X /
>>
Menu Structure Slide 2/3
Menu items which have subordinate menu levels are suffixed with the ‘/’character
Menu items without a suffix are commands in the current menu
Menu navigation is achieved by typing the desired menu item name, or a shorthand version of this name
UI is line oriented, and as such it requires a carriage return after each user request
The user interface is not case sensitive
Menu Structure Slide
3/3
When the menu level changes, the new level of the menu structure is displayed.
Command parameters to be entered by the user– Error Messages– Help text
Error message displayed in case of unrecognized the user input– Menu is displayed again
Menu Navigation
Two special characters can be used to move around the menu system:
1. The asterisk character (*)– Moves the user up one level in the command hierarchy
2. The tilde character (~)– Moves the user to the top (root) of the command hierarchy
Command Shortcuts Slide 1/2
There are three methods of entering commands:
1. The user can type the entire command, such as ‘config’
2. The user can type three or more letters to uniquely identify the command
– First letters of the command name
3. The user can type a shortcut for the command– Displayed in upper case in the command name– If numbers are included in the shortcut, the entire shortcut is shown
in square brackets after the command name
Command Shortcuts Slide 2/2
Multiple menu level navigation possible with a single entry– Achieved by typing a sequence of space-separated
commands– Example:–c e i v
This is the equivalent of typing:config external_alarm input view
Parameter Notation Slide 1/2
Parameter names are shown inside angle brackets for most purposes
– Example <SDH_port>
Brackets excluded if a parameter is listed in the parameter column of a
command table
Text parameters are shown inside single quote marks indicating text that must be typed literally
Alternative parameters are indicated by a pipe (|) character– Example SDH_port | PDH_port
Parameter Notation Slide 2/2
Optional parameters are shown inside square brackets([])– Example – SDH_AU4 HP_path_label [CRC]– Indicates that the <SDH_AU4> parameter and
<HP_path_label> parameter are both required, but that the <CRC> parameter is optional
PDH Ports
SDH Tributary Payload
SDH Aggregate Payloads
SDH Higher Order Payload
SDH Ports
Message Types
Response (non-autonomous) messages– Direct response to user commands– Numbered– Short explanatory message followed by optional text– Example :
Message TypesAutonomous messages
– Autonomous messages are initiated in the NE – Sent to all logged in users.– Users may enable or disable display of these messages on a per session
basis– These messages are displayed by default.
Example
Two Types– Alarm Events– Non Alarm Events
Autonomous Messages
Alarm Events– Notify the user of an alarm being raised or cleared– Format
Non Alarm Events
UI Access
Default Setting
The Configuration Manager and System Engineer classes have compulsory automatic logout– Initially set to the default setting of fifteen minutes– Can be changed using the session menu
Logging In
The TN-1X supports three user sessions from the Preside EC-1 Element Controller, and one from the CAT– Only one system engineer login is permitted– Either Preside EC-1 Element Controller or CAT (but not from
both simultaneously)
The configuration manager and status manager classes can have more than one login
CAT Login Procedure
Main User Menu
Logging OutLogout can occur either manually or
automatically:– Manual logout
•This is achieved using the Logout command, which is available from the top-level (root) menu
•No confirmation is requiredTN-1X/>>l 8 Bye;
– Automatic logout– This occurs after no activity has occurred for a
predetermined period– Automatic logout period can be adjusted using ‘Session’
menu commands
Menu Options
Configuration Menu
Diagnostic Menu
Maintenance Menu
View Status Menu
Session Menu
Administration Menu
Configuration Command Hierarchy
Diagnostic Command Hierarchy
Maintenance Command Hierarchy
View Status Command Hierarchy
Session Command Hierarchy
Administration Command Hierarchy
Diagnostics
Loopbacks
2 Mbps Trib Unit
Remote Loopbacks–Trib input data (after the line interface but prior to HDB3 decoding) is routed to the tributary output (after the HDB3 coding but prior to the line interface)
–The tributary input data is still processed by the rest of the unit unless the ‘Local’ loopback is enabled
–Note: Selecting the ‘Remote’ loopback when the selected tributary has no input will cause a ‘PPI-TF’ alarm to be raised
2 Mbps Trib Unit
Local Loopbacks– Trib output data (after the HDB3 coding but prior to the line
interface) is routed to the tributary input (after the line interface but prior to HDB3 decoding)
– The tributary output data is still applied to the line interface and output from the unit unless the ‘Remote’ loopback is enabled
– Note 1: •For each trib, only the ‘Remote’ or the ‘Local’ loopbacks can operate at a given time
•If both loopbacks are selected for a given trib the ‘Local’ loopback will not operate
2 Mbps Trib Unit - Precautions•Note 2:
– Do not apply a ‘Local’ loopback for a trib selected as the active synchronization source, otherwise the multiplexer will lose synchronization
•Note 3:– When a local loopback is active on a 2 Mbit/s port, AIS is not detected on
this port
34/45 Mbps Trib Unit
Remote Loopbacks– When enabled, tributary input data (after the line interface
but prior to line decoding) is routed to the tributary output (after the line coding but prior to the line interface)
– The tributary input data is still processed by the rest of the unit unless the ‘Local’ loopback is enabled
34/45 Mbps Trib Unit
Local loopbacks– When enabled, tributary output data (after the line coding
but prior to the line interface) is routed to the tributary input (after the line interface but prior to line decoding)
– The tributary output data is still applied to the line interface and output from the unit unless the ‘Remote’ loopback is enabled.
– Precautions
STM-1 Agg Unit/STM-1 Trib UnitRemote loopbacks
– When enabled, the STM-1 input data (after the STM-1 interface and prior to the SOH termination) is routed to the STM-1 output (after the SOH insertion and prior to the STM-1 interface)
– The normal STM-1 output is disabled– This loopbacks the data from the receiver to the transmitter– The STM-1 input data from the receiver is still processed by the rest of
the unit.
Local loopbacks– When enabled, the STM-1 output data (after the SOH insertion and
prior to the STM-1 interface) is routed to the STM-1 input (after the STM-1 interface and prior to the SOH termination)
– The normal input from the receiver being disabled– This loopbacks the STM-1 data towards the Payload Manager
Loopback Alarm
An ‘NE-Loopback_Alarm’ is raised whenever one or more loopbacks are enabled
The alarm report will not indicate which port the loopback is on
Use the loopback view command to identify active loopbacks
This alarm clears once all loopbacks have been disabled
EOW Operation Slide 1/4
The EOW system uses a calling feature which uses the format ‘n n #’, where :
– n is a digit between 0 and 9 and # is the dial termination character– The two ‘n’ digits provide a unique two-digit site-identification code
which is set via a DIL switch on the EOW Unit– This code is used to match against the incoming DTMF digit sequence
Selective calling of an individual site is made by :– Taking the handset off-hook– Waiting for a dialing tone– Dialing the site-identification code– Dial termination character (that is, ‘n n #’)
EOW Operation Slide 2/4
Group dialing and broadcast call feature:– Employs use of the wild card character ‘*’ as follows:
•Entering the sequence ‘* n #’ rings all sites ending with the ‘n’ digit (group call)
•Entering the sequence ‘n * #’ rings all sites starting with the ‘n’ digit (group call)
•Entering the sequence ‘* * #’ which will make all nodes ring (broadcast call)
EOW Operation Slide 3/4
The EOW Unit contains a green LED and a buzzer which indicates the status of the EOW system at that node as follows:– LED and buzzer OFF - EOW channel not in use– LED ON, buzzer OFF - EOW channel in use– LED flashing, buzzer sounding - incoming EOW call– Note 1: There is no time-out for the LED and buzzer, they
remain active until the call is answered (handset taken off-hook) or the caller’s handset is replaced
– Note 2: The LED at the node initiating an EOW call is not illuminated, this indicates that it is the node which configured the system
EOW Operation Slide 4/4
If a path section is invalid (out of alignment), the communication path is disconnected
If working in a protected configuration (protected terminal or ring) and the communication path is broken, EOW communication is still possible to all multiplexers
– May be necessary to re-initialize the call (that is, there is no automatic switching to protect to a call)
– Note: If the communication path is re-established after a call has been re-initiated, it is possible that a ‘howl’ will be heard in the handset earpiece
– If this occurs, the call must be re-initiated
Performance Monitoring
Provides two types of parity error counts–Bit Counts
•Sum of all BIP errors within a count period – 1 sec
–Block Counts•Sum of all error detected BIP blocks within a count period – 1 sec
Performance Counts
Errored Seconds (ES)– An ES is a second in which at least one anomaly
(parity error/code violation) or performance defect (alarm) occurs
– The total number of errors is not recorded
Severely Errored Seconds (SES)– An SES is a second in which either a threshold level
of anomalies is exceeded or a performance defect occurs
– The actual number of errors within this second is not recorded
Performance Counts
Background Block Errors (BBE)– A BBE is a block (not included in a SES) in which
there is an anomaly
Unavailable Seconds (UAS)– A UAS is any second which forms part of a period of
unavailable time (UAT)– A period of UAT starts with the onset of ten
consecutive SESs (included in UAT)– The period of UAT ends when there are ten
consecutive non-SES seconds (not included in the UAT).
Performance Counts
Out Of Frame (OOF) seconds– A OOF second is recorded when one or more out-of-frame
condition is detected within the RSOH
Pointer Justification Events (PJE)– A PJE is recorded when a positive or negative movement of a
payload pointer within an STM-1 frame is detected– The bytes that point to the payload will vary depending on
thepayload– The total number of negative PJEs is also recorded– The difference between these two counts identifies the
number of positive pointer movements
Performance Counts
Assessed Seconds (AS)–The AS is the number of seconds during which the–performance monitoring statistics were accumulated
(equivalent to the length of the performance monitoring period)
–Performance monitoring period is terminated on reboot
Performance Monitoring Points
Thank You!