IP RAN Description

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RAN

IP RAN Description

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Date 2008-07-30

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Copyright Huawei Technologies Co., Ltd. 2008. All rights reserved.

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IP RAN Description Contents

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i

Contents

1 IP RAN Change History.......................................................................................................1-1

2 IP RAN Introduction.............................................................................................................2-1

3 IP RAN Principles ............................ ............................ ............................. ........................... .3-1

3.1 IP RAN Application Scenarios ................................................................................................................ 3-13.1.1 Iub over TDM Network ................................................................................................................. 3-1

3.1.2 Iub over IP Network....................................................................................................................... 3-2

3.1.3 Iub over Hybrid IP Transport Network ........................................................................................... 3-3

3.1.4 Iub over IP/ATM Network ............................................................................................................. 3-4

3.1.5 Iu/Iur over IP Network ................................................................................................................... 3-5

3.2 IP RAN Protocol Stacks.......................................................................................................................... 3-5

3.2.1 Protocol Stack of Iub (over IP)....................................................................................................... 3-5

3.2.2 Protocol Stack of Hybrid Iub (over IP /TM)........ ........ ......... ......... ......... ........ ....... ........ ....... ......... 3-10

3.2.3 Protocol Stack of Iu-CS (over IP)................................................................................................. 3-13

3.2.4 Protocol Stack of Iu-PS (over IP) ................................................................................................. 3-14

3.2.5 Protocol Stack of Iur (over IP)...................................................................................................... 3-15

3.2.6 Protocols of Data Link Layer ....................................................................................................... 3-16

3.3 IP Addresses and Routes of IP RAN...................................................................................................... 3-17

3.3.1 Two Networking Types on the Iub/Iur/Iu-CS/Iu-PS Interfaces......... ....... ........ ....... ........ ....... ......... 3-17

3.3.2 Route on the Iub/Iur/Iu-CS/Iu-PS Interface..... ......... ........ ....... ......... ......... ......... ......... ......... ......... 3-19

3.3.3 IP Addresses for SCTP Links and IP Paths Between RNC and NodeB............ ....... ......... ........ ....... 3-19

3.4 IP RAN QoS......................................................................................................................................... 3-20

3.4.1 Admission Control and Congestion Control.................................................................................. 3-21

3.4.2 Differentiated Service .................................................................................................................. 3-21

3.4.3 PQ and RL................................................................................................................................... 3-21

3.5 IP RAN VLAN..................................................................................................................................... 3-22

3.5.1 Ensuring Security ........................................................................................................................ 3-22

3.5.2 Providing Priority Service............................................................................................................ 3-23

3.6 IP RAN FP-Mux................................................................................................................................... 3-24

3.7 IP RAN Header Compression................................................................................................................ 3-25

3.7.1 ACFC.......................................................................................................................................... 3-25

3.7.2 PFC............................................................................................................................................. 3-25

3.7.3 IPHC........................................................................................................................................... 3-25



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3.8 IP RAN Redundancy ............................................................................................................................ 3-26

3.8.1 Single-Homing Layer 3 Networking............................................................................................. 3-26

3.8.2 Dual-Homing Layer 3 Networking ............................................................................................... 3-26

3.8.3 Advantages and Disadvantages of the Networking......... ......... ........ ....... ........ ....... ........ ....... ........ . 3-27

3.8.4 Configuration on the RNC Side.................................................................................................... 3-27

3.8.5 Fault Detection.. .......................................................................................................................... 3-28

3.9 IP RAN Load Sharing........................................................................................................................... 3-28

3.9.1 Load Sharing Layer 3 Networking ............................................................................................... 3-28

3.9.2 Advantage and Disadvantage of the Networking......... ......... ......... ......... ........ ....... ........ ....... ........ . 3-29

3.9.3 Configuration on the RNC Side.................................................................................................... 3-29

3.10 IP RAN DHCP ................................................................................................................................... 3-29

3.11 IP RAN Transport Capabilities............................................................................................................ 3-30

3.11.1 RNC IP Transport Capabilities ................................................................................................... 3-30

3.11.2 BBU IP Transport Capabilities ................................................................................................... 3-31

3.11.3 Macro NodeB IP Transport Capabilities...................................................................................... 3-32

4 IP RAN Parameters ...................... ............................ ............................ ............................ .....4-1

5 IP RAN Reference Documents ..................... ............................ ............................. ..............5-1



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1-1

1 IP RAN Change HistoryIP RAN Change History provides information on the changes between different document

versions.

Document and Product Versions

Document Version RAN Version RNC Version NodeB Version

02 (2008-07-30) 10.0 V200R010C01B061 V100R010C01B050

V200R010C01B041

01 (2008-05-30) 10.0 V200R010C01B051 V100R010C01B049

V200R010C01B040

Draft (2008-03-20) 10.0 V200R010C01B050 V100R010C01B045

There are two types of changes, which are defined as follows:

l Feature change: refers to the change in the IP RAN feature of a specific product version.

l Editorial change: refers to the change in information that was already included or theaddition of information that was not described in the previous version.

02 (2008-07-30)

This is the document for the second commercial release of RAN10.0.

Compared with 01 (2008-05-30) of RAN10.0, issue 02 (2008-07-30) of RAN10.0

incorporates the changes described in the following table.

ChangeType

Change Description Parameter Change

Featurechange

More information about NodeB Iub

interface boards is added. For details,

see chapter 2 "IP RAN

Introduction", and section 3.1 "IP

RAN Application Scenarios".

None.



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ChangeType


The description of IP addresses for

SCTP links and IP paths for NodeBV200R010 is added to section 3.3 IPAddresses and Routes of IP RAN.

None.

None. The parameters modified are listed as

follows:

l Signalling link model is modified toSignalling link mode.

l IU trans bearer type is modified to

IU transfers bearer type.

l Next hop IP address is modified toForward route address.

l IP Address is modified to NodeBIP_TRANS IP address and NodeB

ATM_TRANS IP address.

l IP Head compress is modified to IPHeader Compress.

l MCPPP is modified to Multi ClassPPP.

l Bear Type(ADD IUBCP)is modified

to NCP/CCP Bearing Type.

None. The parameters added are listed as

follows:

l IUB trans bearer type

l IP Trans Apart Ind

l Backup port IP address

l Backup port mask

l Backup port gateway IP address

l Signal Priority

A parameter list is added. See

chapter 4 IP RAN Parameters.

None.

Editorial

change

None. None.

01 (2008-05-30)

This is the document for the first commercial release of RAN10.0.

Compared with draft (2008-03-20) of RAN10.0, issue 01 (2008-05-30) of RAN10.0

incorporates the changes described in the following table.



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ChangeType


IP transport capabilities of DBS3900

and iDBS3900 are added to 3.11 IPRAN Transport Capabilities.

None.

Information of NodeB

V200R010C01B040 is added to 2 IPRAN Introduction.

None.

The parameter is changed in 3.8 IP

RAN Redundancy.

The renamed parameters are listed as

follows:

Times of out-time of BFD packet is

modified to detect multiplier of BFDpacket.

The parameter is changed in 3.6 IPRAN FP-Mux. The changed parameter is listed asfollows:

Mux package number is changed toMaximum Frame Length.

Feature

change

None. The parameters that are changed to be

non-configurable are listed as follows:

l IUB trans bearer type

l IP Trans Apart Ind

l IUR trans bearer type

l Address and control field compress

l Address & Control Field Compress

l Protocol field compress (NodeB)

l Protocol field compress (RNC)

l VLAN Tag (NodeB)

l Signaling priority (NodeB)


l Backup port mask


l ARP packet out-time

l ARP packet resend times

Editorial

change

General documentation change:

l The IP RAN Parameters is

removed because of the creation ofRAN10.0 parameter reference.

l The structure is optimized.

None.



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Draft (2008-03-20)

This is a draft of the document for the first commercial release of RAN10.0.

Compared with issue 03 (2008-01-20) of RAN 6.1, this issue incorporates the changesdescribed in the following table.

ChangeType


The port backup mode is changed in

1.3.8 IP RAN Redundancy.

The following parameters are deleted:

l Slot 14 interface board type

l 14 interface board Backup type

The following parameters are added:

l Board type

l Backup

l Port No.

The fault detection is added in 1.3.8

IP RAN Redundancy.


l Check type

l Port work mode

l Min interval of BFD packet send

[ms]

l Min interval of BFD packet

receive [ms]

l Times of out-time of BFD packet

l

ARP packet out-timel ARP packet resend times

The IP interface boards POUa and

UOIa are added in 1.2.1 IP RAN

Introduction.

None

IP RAN FP-Mux is added in 1.3.6 IPRAN FP-Mux.


l FPMUX flag

l Max subframe length

l Mux package length

l FPTIME

Feature

change

The configuration on the RNC side is

changed in 1.3.9 IP RAN Load

Sharing.

The following parameter is deleted:

l 14 interface board Backup type

The following parameter is added:

l Backup



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ChangeType


In Protocol Stack of Iub (over IP), the

NCP/CCP Bearing Type parameterin the ADD IUBCP command is

renamed as Bear Type. The SET

OMCH (BTS3812E, BTS3812AE,BBU3806, BBU3806C) command is

changed to ADD OMCH

(BTS3812E, BTS3812AE,

BBU3806, BBU3806C).

The following parameter is deleted:

l NCP/CCP Bearing Type

The following parameter is added:

l Bear Type

General documentation change:

Implementation information has beenmoved to a separate document.

NoneEditorial

change

Transport Security of IP RAN ismerged into 1.3.5 IP RAN VLAN

None



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IP RAN Description 2 IP RAN Introduction



2-1

2 IP RAN IntroductionThe IP Radio Access Network (RAN) feature enables IP transport on the Iub, Iur, and Iu

interfaces. This makes it possible for the operators to use their existing IP networks in a larger

and more flexible capacity. In this way, network deployment costs are reduced.

The most widely used data communication networks are based on IP transport. Apart from

being more economical than the Asynchronous Transfer Mode (ATM) network, the IP

networks offer multiple access modes and provide enough transmission bandwidth for high

speed data services, such as High Speed Downlink Packet Access (HSDPA).

IP Interface Boards

To implement the IP RAN feature, the RNC and the NodeB must be configured with the

related IP interface boards. The IP interface boards are as follows:

l IP interface boards for the RNC

PEUa

FG2a

GOUa

UOIa

POUa

l IP interface board for the NodeB

The HBBU of earlier versions provides Fast Ethernet (FE) ports.

Therefore, no hardware change is necessary.

The BTS3812E and the BTS3812AE require the Universal Transport Interface Unit

(NUTI) board.

The NUTI board provides eight E1/T1 ports and two FE ports.

The WMPT board provides 4 E1/T1 ports and 2 FE ports, the UTRP board provides 8

E1/T1 ports.

Numbering Schemes

Numbering schemes are used for this feature for FE, GE and E1/T1 ports of the NodeB and

the RNC, and for the RNC Point-to-Point Protocol (PPP) links.

Numbering Scheme for FE, GE and E1/T1 Ports



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Table 2-1 describes the numbering scheme for the FE, GE, and E1/T1 ports on the NodeB and

the RNC.

Table 2-1Numbering scheme for the FE, GEand E1/T1 ports on the NodeB and the RNC

Board Port Type and Number

PEUa E1/T1: 0 to 31

FE: 0 to 7FG2a

Electrical GE: 0 to 1 (corresponding to 0 and 3 of the FE port number).

GOUa Optical GE: 0 to 1

UOIa Unchannelized optical STM-1/OC-3c: 0 to 3

E1: 0 to 125

RNC

POUa

T1: 0 to 167

FE: 0 to 1NUTI

E1/T1: 0 to 7

FE: 0 to 1BBU

E1/T1: 0 to 7

FE: 0 to 1WMPT

E1/T1: 0 to 3

NodeB

UTRP E1/T1: 0 to 7

NOTE:

BBU = Baseband Unit

Numbering Scheme for RNC PPP Links

The numbering scheme that corresponds to the PEUa, POUa, and UOIa for PPP links at the

RNC is as follows:

l PEUa: 0 to 127

l POUa: 0 to 167

l UOIa: 0 to 3

Numbering Scheme for NodeB PPP Links

The numbering scheme that corresponds to the HBBU, NUTI, WMPT, and UTRP for PPP

links at the NodeB is as follows:

l HBBU: 0 to 15

l NUTI: 0 to 15

l WMPT: 0 to 7

l UTRP: 0 to 15



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2-3

Impactl Impact on System Performance

This feature has no impact on system performance.

l Impact on Other Features

This feature has no impact on other features.

Network Elements Involved

Table 2-2 describes the Network Elements (NEs) involved in IP RAN.

Table 2-2NEs involved in IP RAN

UE NodeB RNC MSC Server MGW SGSN GGSN HLR

NOTE:l: not involved

l : involved

UE = User Equipment, RNC = Radio Network Controller, MSC = Mobile Service Switching Center,MGW = Media Gateway, SGSN = Serving GPRS Support Node, GGSN = Gateway GPRS SupportNode, HLR = Home Location Register



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3-1

3 IP RAN PrinciplesThe following lists the contents of this chapter.

l IP RAN Application Scenarios

l IP RAN Protocol Stacks

l IP Addresses and Routes of IP RAN

l IP RAN QoS

l IP RAN VLAN

l IP RAN FP-Mux

l IP RAN Header Compression

l IP RAN Redundancy

l IP RAN Load Sharing

l IP RAN DHCP

l IP RAN Transport Capabilities

3.1 IP RAN Application ScenariosThe IP RAN application scenarios consist of:

l Iub over Time Division Multiplexing (TDM) Network

l Iub over IP Network

l Iub over hybrid IP transport Network

l Iub over IP/ATM Network

l Iu/Iur over IP Network.

3.1.1 Iub over TDM Network

Figure 3-1 shows the TDM networking mode.



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Figure 3-1TDM networking mode

In the TDM networking mode, the RNC uses the PEUa and POUa as the Iub interface boards,

and the NodeB uses the HBBU, NUTI, WMPT, and UTRP as the Iub interface boards. The

RNC and NodeBs support IP over E1/T1, which is based on Plesiochronous Digital Hierarchy

(PDH) orSynchronous Digital Hierarchy (SDH).

The TDM network ensures the reliability, security, and QoS of the Iub interface data

transmission, but the costs of E1 transport are relatively high.

3.1.2 Iub over IP Network

Figure 3-2 shows the IP networking mode.

Figure 3-2IP networking mode

In the IP networking mode:

l The FG2a or GOUa board of the RNC serves as the Iub interface board and supportsboard backup, FE/GE port backup, or FE/GE port load sharing.

l The HBBU, NUTI, or WMPT board of the NodeB serves as the Iub interface board, and

the NodeB is connected to the IP network through FE port.

The IP network can be any of the following types:

l Layer 2 network, for example, metropolitan area Ethernet and VPLS



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l Layer 3 network, for example, IP/MPLS/VPN

l Multi-Service Transmission Platform (MSTP) network

3.1.3 Iub over Hybrid IP Transport NetworkFigure 3-3 shows the hybrid IP networking mode.

Figure 3-3Hybrid networking mode

In this networking mode:

l The PEUa/POUa and FG2a/GOUa boards of the RNC serve as the Iub interface boards

and support FG2a/GOUa board backup, FE/GE port backup, or FE/GE port load sharing.

The POUa supports the board with Multiplex Section Protection (MSP) backup mode,and port wih MSP backup mode.

l The NodeB is connected to the IP network through FE port and uses the HBBU, NUTI orWMPT as the Iub interface board.

l The NodeB is connected to the TDM network through E1/T1 port and uses the HBBU,NUTI, UTRP, or WMPT as the Iub interface board.

In Hybrid IP transport, services with different QoS requirements can be transmitted in

different paths. The two paths from the RNC to the NodeB are connected to two different

networks through different ports, or through the same port that is connected to the external

data equipment according to Differentiated Service Code Point (DSCP).

l Low QoS network (IP network, such as Ethernet)

The PS interactive and background services that have low QoS are carried on the lowQoS network. When the bandwidth of the low QoS network is limited, low QoS servicesare carried on the high QoS network.

l High QoS network (TDM network, such as PDH and SDH)

The control plane data, Radio Resource Control (RRC) signaling, common channel data,

Circuit Switched (CS) services, Packet Switched (PS) conversational services, and

streaming services are carried on the high QoS network. When the bandwidth of the high

QoS network is limited, the RNC reduces the rate of the low QoS services that are

carried on the high QoS network, or the RNC rejects the access of high QoS services if

no low QoS services are carried on the high QoS network.



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The hybrid transport network is flexible in terms of meeting different QoS requirements, but it

is complicated to manage.

3.1.4 Iub over IP/ATM Network

With the development of data services, especially with the introduction of High Speed Packet

Access (HSPA), the Iub interface has an increasing demand for the bandwidth. A single ATM

network has high costs. IP transport saves the transmission cost but provides a lower

guarantee of QoS than ATM transport does. Therefore, the ATM/IP networking mode is

introduced. Services with different QoS requirements are transmitted on different types of

network.

Figure 3-4 shows the ATM/IP networking mode.

Figure 3-4ATM/IP networking mode

The ATM/IP networking mode allows hybrid transport of services with different QoS

requirements. High QoS services, such as voice services, streaming services, and signaling,are transmitted on the ATM network. Low QoS services, such as PS Best Effort (BE) services,

are transmitted on the IP network.

The ATM and IP interface boards of the RNC must be configured to support this networking

mode. The ATM interface board can be the AEUa, AOUa, or UOIa. The IP interface board can

be the FG2a, GOUa, UOIa, POUa, or PEUa.

l The RNC is connected to the ATM network through the E1/T1 or STM-1 port.

l The RNC is connected to the IP network through the FE/GE port.

The NodeB is connected to the ATM/IP networks through the ATM and IP interface boardsrespectively. The ATM interface board can be the HBBU, NUTI, or WMPT. The IP interface

board can be the HBBU, NUTI, WMPT or UTRP.

l The NodeB is connected to the high QoS ATM network through E1/T1 port.

l The NodeB is connected to the low QoS IP network through FE port.

The NodeB cannot be connected to both the ATM network and the IP network simultaneously throughE1/T1 ports on the same board.

In the ATM/IP network, the ATM network ensures the QoS, while the IP network reduces the

transmission costs and fulfills the requirement of high-speed data services for high bandwidth

on the Iub interface. On the other hand, the ATM/IP network requires the maintenance of both

the ATM and the IP networks; thus the maintenance is more complex and expensive.



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3.1.5 Iu/Iur over IP Network

Figure 3-5 shows the Iu/Iur networking mode.

Figure 3-5Iu/Iur over IP network

In this networking mode, the FG2a, GOUa, or UOIa board of the RNC serves as the Iu or Iur

interface board and supports board backup, FE/GE port backup, or FE/GE port load sharing.

The IP network can be any of the following three types:

l Layer 2 network, for example, metropolitan area Ethernet and VPLS

l Layer 3 network, for example, IP/MPLS VPN

l Multi-Service Transmission Platform (MSTP) network

3.2 IP RAN Protocol StacksThe IP RAN protocol stacks consist of:

l Protocol Stack of Iub (over IP)

l Protocol Stack of Hybrid Iub (over IP /TM)

l Protocol Stack of Iu-CS (over IP)

l Protocol Stack of Iu-PS (over IP)

l Protocol Stack of Iur (over IP)

l Protocols of Data Link Layer

3.2.1 Protocol Stack of Iub (over IP)

The protocol stack of Iub (over IP) is the Iub IP protocol. Data transmission on the Iub

interface is based on the IP transport.



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Figure 3-6Protocol stack of Iub (over IP)

Figure 3-6 shows the protocol stack of Iub (over IP).

l The control plane data is carried on the SCTP link.

l The user plane data is carried on the IP path.

l The data link layer can use IP over E1/T1, IP over Ethernet, IP over E1/T1 over SDH, orIP over SDH.

Transport Mode Configuration on the RNC Side

To support Iub (over IP), associated parameters are configured as follows:

l The IUB trans bearer type parameter is set to IP_TRANS.

l The IP Trans Apart Ind parameter is set to SUPPORT orNOT_SUPPORT to specify

whether the hybrid IP transport is applied.

l The Adjacent Node Type parameter is set to IUB.

l The Transport Type parameter is set to IP.

Transport Mode Configuration on the NodeB Side

If E1/T1 is used for transport on the NodeB side, the Bearing Mode parameter for E1/T1

must be set to IPV4.

IP Path

An IP path is a group of connections between the RNC and the NodeB. An Iub interface has at

least one IP path. It is recommended that more than one IP path be planned.



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IP Path Configuration on the RNC Side

The parameters for establishing an IP path on the RNC side are as follows:

l

Local IP addressl Peer IP address

l Peer subnet mask

l IP path type

l DSCP

IP Path Configuration on the NodeB Side

The parameters for establishing an IP path on the NodeB side are as follows:

l Port Type

l NodeB IP address

l RNC IP address

l Traffic Type

l Differentiated Services Code Point

SCTP Link

An SCTP link carries signaling messages on the Iub interface. The signaling messages carried

on the SCTP link are classified into NCP and CCP, as described in Table 3-1.

Table 3-1Signaling messages carried on SCTP links

Type Description

NCP An NCP carries common process messages of NBAP over the Iub interface. An

Iub interface has only one NCP.

CCP A CCP carries dedicated process messages of NBAP over the Iub interface. An

Iub interface may have multiple CCPs. The number of CCPs depends on networkplanning.

NOTE:NCP = NodeB Control Port, CCP = Communication Control Port

The Signalling link mode of an SCTP link can be SERVERorCLIENT.

SCTP Link Configuration on the RNC side

Iub control plane data is carried on the SCTP link. An SCTP endpoint can use two local

addresses, but these two must use the same port number. This mechanism is called

multi-homing.

In Iub IP transport, the Signalling link mode parameter has to be set to SERVERwhen you

configure an SCTP link on the RNC side.

The other parameters for establishing an SCTP link on the RNC side are as follows:



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l First local IP address

l Second local IP address

l First destination IP address

l Second destination IP address

l Local SCTP port No.

l Destination SCTP port No.

The second local IP address and the second peer IP address must be configured together.

NCP and CCP Configuration on the RNC Side

On the RNC side, the NodeB Control Port (NCP) link and Communication Control Port (CCP)

link are carried on the SCTP link. That is, the Bearing link type parameter has to be set to

SCTP.

The parameters for establishing the NCP link and CCP link are as follows:

l SCTP link No.

l Bearing link type

SCTP Link Configuration on the NodeB Side

The parameters for establishing an SCTP link on the NodeB side are as follows:

l Local IP address

l Second Local IP address

l Peer IP address

l Second Peer IP address

l Local SCTP Port

l Peer SCTP Port

NCP and CCP Configuration on the NodeB Side

On the NodeB side, the NCP link and CCP link are carried on the SCTP link. That is, the

NCP/CCP Bearing Type parameter has to be set to IPV4.

OM Channel

OM channel is used to maintain and configure the NodeB remotely. There are two methods to

configure routes for the OM channel on the Iub interface:

l Configuring routes between the M2000 and the NodeB through the RNC.

l Configuring routes between the M2000 and the NodeB not through the RNC.

Figure 3-7 shows an example of configuring routes between the M2000 and the NodeB

through the RNC.



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Figure 3-7Example of configuring routes between the M2000 and the NodeB through the RNC

Figure 3-7 takes layer 2 networking on the Iub interface as an example. When layer 3 networking isapplied to the Iub interface, the IP interface board and the NodeB communicate through a router.

If the OM subnet where the M2000 is located is connected to the IP network that covers the

NodeB, the routes can be configured between the M2000 and the NodeB not through the RNC.

Figure 3-8 shows an example of configuring routes between the M2000 and the NodeB not

through the RNC.

Figure 3-8Example of configuring routes between the M2000 and the NodeB not through theRNC

OM Channel Configuration on the RNC Side

For detailed information about the OM channel configuration on the RNC side, see 3.10 IP

RAN DHCP.

OM Channel Configuration on the NodeB Side

The parameters for establishing an OM channel on the NodeB side are as follows:

l Local IP Address

l Local IP Mask



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l Peer IP address

l Peer IP Mask

l Bear Type

Other Data Configuration on the RNC Side and NodeB Side

To enable Iub (over IP) transport, the other data (such as the physical layer data, data link

layer data, mapping between transmission and traffic, and factor table) has to be configured.

For detailed information about these configurations, refer to theRNC Initial Configuration

Guide and theNodeB Initial Configuration Guide.

3.2.2 Protocol Stack of Hybrid Iub (over IP /TM)

In hybrid Iub transmission (over IP/ATM), data transmission on the Iub interface is based on

both ATM transport and IP transport.

Figure 3-9Protocol stack of Iub (over IP/ATM)

Figure 3-9 shows the protocol stack of Iub (over IP/ATM).

With the introduction of Iub (over IP/ATM), the data between RNC and NodeB can be

transmitted on two networks: ATM network and IP network.

l On the ATM network

Iub control plane data is carried on the SAAL link.

Iub user plane data is carried on the AAL2 path.

l On the IP network

Iub control plane data is carried on the SCTP link.



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Iub user plane data is carried on the IP path.


To support Iub (over ATM/IP), associated parameters are configured as follows:

l The IUB trans bearer type parameter is set to ATMANDIP_TRANS.

l The Adjacent Node Type parameter is set to IUB.

l The Transport Type parameter is set to ATM_IP.

IP Path and SCTP Link Configuration on the RNC and NodeB Sides

The parameters for IP path and SCTP link on the RNC and NodeB sides are similar to those

for Iub (over IP). For detailed information, see 3.2.1 Protocol Stack of Iub (over IP).

AAL2 Path

An AAL2 path is a group of connections between the RNC and the NodeB. An Iub interface

has at least one AAL2 path. It is recommended more than one AAL2 path be planned.

An AAL2 path is carried on a PVC. The PVC identifier (VPI/VCI) and other attributes of the

PVC must be negotiated between the RNC and the NodeB.

AAL2 Path Configuration on the RNC Side

The parameters for establishing an AAL2 path on the RNC side are as follows:

l Adjacent node ID

l AAL2 path ID

For detailed information about AAL2 path resources, see ATM Transmission Resources.

AAL2 Path Configuration on the NodeB Side

The parameters for establishing an AAL2 path on the NodeB side are as follows:

l AAL2 path ID

l Node Type

l Path Type

SAAL Link of User Network Interface (UNI) Type

An SAAL link of UNI type carries signaling messages on the Iub interface. The signalingmessages carried on the SAAL links are categorized into NCP, CCP, and ALCAP, as described

in Table 3-2:

Table 3-2The type of the signaling messages carried on the SAAL links

Type Description

NCP An NCP carries common process messages of NBAP over the Iub interface. The

Iub interface has only one NCP.



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Type Description

CCP A CCP carries dedicated process messages of NBAP over the Iub interface. The

Iub interface may have multiple CCPs. The number of CCPs depends on

network planning.

ALCAP The ALCAP is also called Q.AAL2. Typically, the Iub interface has one

ALCAP.

An SAAL link of UNI type is carried on a PVC. The PVC identifier (VPI/VCI) and other

attributes of the PVC must be negotiated between the RNC and the NodeB.

SAAL Link Configuration on the RNC Side

The parameters for establishing an SAAL link on the RNC side are described as follows:

l Interface type

l Bearing VPI

l Bearing VCI

NCP and CCP Configuration on the RNC Side

It is recommended that all Iub control plane data be carried on the ATM network when Iub is

carried on both ATM and IP. In this case, Bearing link type of the NCP and CCP should be

set to SAAL.

l Bearing link type

l SAAL link No.

SAAL Link Configuration on the NodeB Side

The parameters for establishing an SAAL link on the NodeB side are as follows:

l Bearing VPI

l Bearing VCI

NCP and CCP Configuration on the NodeB Side

It is recommended that all Iub control plane data be carried on the ATM network when Iub is

carried on both ATM and IP. In this case, NCP/CCP Bearing Type of the NCP and CCP

should be set to ATM.

OM Channel Configuration on the RNC and NodeB Sides

The parameters for OM channel on the RNC side and NodeB side are similar to those for Iub

(over IP). For detailed information, see 3.2.1 Protocol Stack of Iub (over IP).

Other Data Configuration on the RNC and NodeB Sides

To enable Iub (over ATM/IP) transport, the other data (such as the physical layer data, data

link layer data, mapping between transmission and traffic, and factor table) has to be



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configured. For detailed information about these configurations, refer to theRNC Initial

Configuration Guide and theNodeB Initial Configuration Guide.

3.2.3 Protocol Stack of Iu-CS (over IP)

The protocol stack of Iu-CS (over IP) is the Iu-CS IP protocol. Data transmission on the Iu-CS


Figure 3-10Protocol stack of Iu-CS (over IP)

Figure 3-10 shows the protocol stack of Iu-CS (over IP).




To support Iu-CS (over IP), associated parameters are configured as follows:

l The CN domain ID parameter is set to CS_DOMAIN.

l The IU transfers bearer type parameter is set to IP_TRANS.

l The Adjacent Node Type parameter is set to IUCS.



The parameters for IP path on the RNC side are similar to those for Iub (over IP). For details,

see 3.2.1 Protocol Stack of Iub (over IP).



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SCTP Link Configuration on the RNC Side

The parameters for SCTP link on the RNC side are similar to those for Iub (over IP). For

details, see 3.2.1 Protocol Stack of Iub (over IP).

Other Data Configuration on the RNC Side

To enable Iu-CS (over IP) transport, the other data (such as the physical layer data, data link

layer data, mapping between transmission and traffic, factor table, and data of M3UA) has to

be configured. For details about these configurations, refer to theRNC Initial Configuration

Guide.

3.2.4 Protocol Stack of Iu-PS (over IP)

The protocol stack of Iu-PS (over IP) is Iu-PS IP protocol. Data transmission on the Iu-PS


Figure 3-11Protocol stack of Iu-PS (over IP)

Figure 3-11 shows the protocol stack of Iu-PS (over IP).




To support Iu-PS (over IP), associated parameters are configured as follows:

l The CN domain ID parameter is set to PS_DOMAIN.

l The IU transfers bearer type parameter is set to IP_TRANS.

l The Adjacent Node Type parameter is set to IUPS.




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The parameters for transport mode are similar to those for Iu-CS (over IP). For detailed

information, see 3.2.3 Protocol Stack of Iu-CS (over IP).

IP Path Configuration on the RNC SideThe parameters for IP path on the RNC side are similar to those for Iub (over IP). For detailed

information, see 3.2.1 Protocol Stack of Iub (over IP).


The parameters for SCTP link on the RNC side are similar to those for Iub (over IP). For

detailed information, see 3.2.1 Protocol Stack of Iub (over IP)..


To enable Iu-PS (over IP) transport, the other data (such as the physical layer data, data link

layer data, mapping between transmission and traffic, factor table, and data of M3UA) has tobe configured. For detailed information about these configurations, refer to theRNC Initial

Configuration Guide.

3.2.5 Protocol Stack of Iur (over IP)

The protocol stack of Iur (over IP) is Iur IP protocol. Data transmission on the Iur interface is

based on the IP transport.

Figure 3-12Protocol stack of Iur (over IP)

Figure 3-12 shows the protocol stack of Iur (over IP), where:





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To support Iur (over IP), associated parameters are configured as follows:

lThe Iur Interface Existing Indication parameter is set to TRUE.

l The IUR trans bearer type parameter is set to IP_TRANS.

l The Adjacent Node Type parameter is set to IUR.



The parameters for IP path on the RNC side are similar to those for Iub (over IP). For detailed

information, see 3.2.1 Protocol Stack of Iub (over IP)..


The parameters for SCTP link on the RNC side are similar to those for Iub (over IP). Fordetailed information, see 3.2.1 Protocol Stack of Iub (over IP)..


To enable Iur (over IP) transport, the other data (such as the physical layer data, data link

layer data, mapping between transmission and traffic, factor table, and data of M3UA) has to

be configured. For detailed information about these configurations, refer to theRNC Initial

Configuration Guide.

3.2.6 Protocols of Data Link Layer

The protocols at the data link layer consist of Ethernet, PPP/MLPPP, MCPPP, and PPPMux.

Ethernet

Ethernet is a standard that was jointly released by Digital Equipment Corp., Intel Corp., and

Xerox in 1982. It is the most widely used Local Area Network (LAN) technology based on

TCP/IP and CSMA/CD access method.

The MAC addressing scheme of Ethernet helps to resolve the addressing problem of entities

within the Ethernet. Each MAC address has 48 bits and the addresses are assigned worldwide

under the same rule.

The earliest Ethernet packet encapsulation format complies with Ethernet 802.3 defined by

IEEE and the most common format now is Ethernet II specified by RFC0826. The NodeB and

the RNC can transmit frames in Ethernet II format and receive frames in Ethernet 802.3 andEthernet II formats.

PPP/MLPPP

The PPP provides standard methods for encapsulating the multi-protocol datagrams on

point-to-point links. These datagrams consist of IP, IPX, and Apple Talk.

MLPPP (MP) is used to combine multiple physical links into a logical link. Therefore, it

provides a relatively high bandwidth and facilitates quick data transfer. MLPPP

implementation is shown in Figure 3-13.



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Figure 3-13MLPPP implementation

MCPPP

MCPPP (MC) is an extension of the MLPPP protocol and provides more priorities. Packets

with a higher priority can interrupt the transmission of those with a lower priority. The MC

protocol is implemented in compliance with RFC2686.

The bits, responsible for marking the priority of a packet, in the MLPPP header are not used

in the MLPPP protocol. These bits are the two bits after the E flag bit in the short sequence, or

the four bits after the E flag bit in the long sequence. Packets at each priority level have their

own MLPPP mechanism, for example, independent sequence number and reassembly queue.

l The parameter on the RNC side is MLPPP type.

l The parameter on the NodeB side is Multi Class PPP.

PPPMux

PPPMux encapsulates multiple PPP frames (also called subframes) in a single PPPMux frame.

The subframes in the PPPMux frame are distinguished by delimiters. PPPMux reduces PPP

overhead per packet and improves bandwidth efficiency. PPPMux is implemented in

compliance with RFC3153.

l The parameter on the RNC side is PPP mux.

l The parameter on the NodeB side is PPP MuxCP.

3.3 IP Addresses and Routes of IP RANThis section describes the IP addresses and routes that are required for running an IP RAN

network.

3.3.1 Two Networking Types on the Iub/Iur/Iu-CS/Iu-PSInterfaces

There are two types of networking on the Iub/Iur/Iu-CS/Iu-PS interfaces: layer 2 networking

and layer 3 networking.

Layer 2 Networking

Compared with layer 3 networking, layer 2 networking is simpler. That is because the port IPaddresses of the RNC, NodeB, and neighboring RNC, MGW and SGSN are located in the

same network segment and no route is required.



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Figure 3-14 shows an example of layer 2 networking on the Iub/Iur/Iu-CS/Iu-PS interfaces.

Figure 3-14Layer 2 networking on the Iub/Iur/Iu-CS/Iu-PS interfaces

l IP 1 is the interface IP address on the IP interface board.

l In layer 2 networking mode, the interface IP addresses of the RNC and NodeBs are in the samenetwork segment. A route is not necessary in this case, which makes the networking relativelysimple.

Layer 3 Networking

Figure 3-15 shows an example of layer 3 networking on the Iub/Iur/Iu-CS/Iu-PS interface.

Figure 3-15Layer 3 networking on the Iub/Iur/Iu-CS/Iu-PS interface



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l IP 1 and IP 2 are device IP addresses of the IP interface board. One interface board supports amaximum of five device IP addresses. The device IP addresses configured on the same interfaceboard cannot be located in the same subnet.

l IP 3 and IP 4 are port IP addresses of the IP interface board.

l IP 5 and IP 6 are gateway IP addresses on the RNC side.

l IP 7 is the gateway IP address on the NodeB/neighboring RNC/MGW/SGSN side.

l IP 8 is the IP address of the NodeB/neighboring RNC/MGW/SGSN.

3.3.2 Route on the Iub/Iur/Iu-CS/Iu-PS Interface

On the Iub/Iur/Iu-CS/Iu-PS interface where layer 2 networking is applied, no route is required.

On the Iub/Iur/Iu-CS/Iu-PS interface where layer 3 networking is applied, you should

configure the route, as described in Table 3-3 on the RNC.

Table 3-3Route on the Iub/Iur/Iu-CS/Iu-PS interface

Part Route Description

IP interface board The route travels from the RNC to the network segment where the

NodeB/neighboring RNC/MGW/SGSN is located.

You can run the ADD IPRT command on the RNC to configure the

route. Destination IP address is the address of the network segmentwhere the NodeB/neighboring RNC/MGW/SGSN is located, and

Forward route address, for example, IP 5 or IP 6, is the gateway IPaddress on the RNC side.

3.3.3 IP Addresses for SCTP Links and IP Paths Between RNCand NodeB

Figure 3-16 shows the IP addresses assigned to SCTP links and IP paths between RNC and

NodeB.

Figure 3-16IP addresses for SCTP links and IP paths between RNC and NodeB

IP1-0 and IP2-0: IP addresses for SCTP links on the NodeB side

IP1-1 and IP2-1: IP addresses for SCTP links on the RNC side

IP3-0: IP address for the IP paths on the NodeB side

IP3-1: IP address for the IP paths on the RNC side



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Figure 3-16 shows two interconnected BBUs on the NodeB side as an example. When two

BBUs are interconnected through the EIa ports, the two BBUs are regarded as one NodeB on

the RNC side. On the NodeB side, BBU1, which is connected to the transport network

between RNC and NodeB, is an active BBU, while BBU2 is a standby BBU. The IP addresses

of the NodeB for communicating with the RNC are configured only on BBU1. The data of theIub interface is sent or received through the FE/E1 ports of BBU1, as shown in Figure 3-16.

l You can specify the active BBU and standby BBU by setting the Dual-In-line Package (DIP) switch.For detailed information about the DIP switch, see the description of the DIP switch on the

BBU3806 or DIP switch on the BBU3806C in theDBS3800 Hardware Description.

l Figure 3-16 shows the settings of the IP addresses for the SCTP links and the IP paths for NodeBV100R010. For NodeB V200R010 version, the settings are the same as those for NodeB V100R010.The only difference is that, for NodeB V200R010, there are no interconnected BBUs.

l IP1-0 and IP 2-0 are configured as the first local IP address and the second local IP

address respectively for the SCTP links on the NodeB side. IP1-1 and IP2-1 are

configured accordingly on the RNC side. The first local IP address and the second local

IP address cannot be the same. When the first local IP address for the SCTP links isunavailable, the data on the SCTP links is transmitted through the second local IPaddress.

When the layer 2 or TDM networking is applied, IP1-0, IP1-1, IP2-0, and IP2-1 are

the IP addresses of the port (FE/GE/PPP/MLPPP). IP1-0 and IP1-1 are within thesame network segment, and the same is true for IP2-0 and IP2-1.

When the layer 3 networking is applied, IP1-0 and IP2-0 are the IP addresses of the

FE ports, and IP1-1 and IP2-1 are the device IP addresses. IP1-0 and IP1-1 do notstay within the same network segment, and the same is true for IP2-0 and IP2-1.

l IP paths between RNC and NodeB do not work in backup mode.

When the layer 2 or TDM networking is applied, IP3-0 and IP3-1 are IP addresses ofthe port (FE/PPP/MLPPP). IP3-0 and IP3-1 are within the same network segment.

When the layer 3 networking is applied, IP3-0 is IP address of the FE port and IP3-1is the device IP address. IP3-0 and IP3-1 do not stay within the same networksegment.

3.4 IP RAN QoSThe assurance mechanisms of QoS are implemented at the application layer, IP layer, data

link layer, and physical layer.

Table 3-4 describes the assurance mechanisms of the QoS.

Table 3-4Assurance mechanisms of the QoS

Layer Mechanism

Application layer Admission control and congestion control

IP layer Differentiated Service

Data link layer Priority Queue (PQ)

Physical layer Rate Limiting (RL) at the physical port



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3.4.1 Admission Control and Congestion Control

For detailed information about admission control and congestion control, see Admission

Control and Congestion Control.

3.4.2 Differentiated Service

Figure 3-17 shows the differentiated service process.

Figure 3-17Differentiated service process

Table 3-5 describes the differentiated service process. The classification and adjustment of

traffic usually happen at the network edge.

Table 3-5Differentiated service process

Operation Description

Classifying the service Traffic classification enables different types of services that are

implemented by setting different values.

Metering The data rate is metered and the

subsequent shaping and schedulingare based on the metering.

Marking The packets are marked with

different colors according to TrafficConditioning Agreement (TCA).

Shaping The packets in the traffic flow are

delayed as required by the servicemodel.

Adjusting

the service

Dropping Non-TCA-supportive packets are

dropped.

The adjustment of

service ensures that the

traffic flow involving

differentiated servicescomplies with TCA.

3.4.3 PQ and RL

The principles of PQ and RL are considered together. The PQs are configured automatically in

the NodeB. When the actual bandwidth exceeds the specified bandwidth, the system buffers

the congested data or discards it to ensure a specified bandwidth at the physical port. When

the physical port is congested, the system discards the message with lower priority according

to the PQ principle.

Table 3-6 describes the rules for PQs based on the three Most Significant Bits (MSBs) of the

DSCP.



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Table 3-6Rules for PQs in NodeB

MSBs of the DSCP PQ

110 or 111 The urgent queue is used by default. No manual configuration of the

PQ is necessary.

101 TOP

100 or 011 MIDDLE

010 or 001 NORMAL

0 BOTTOM

The parameters for setting the priorities for data transmission on the NodeB side are as

follows:

l Signal Priority

l OM priority

The RNC IP interface boards (PEUa/FG2a/GOUa/POUa/UOIa) support six priority queues

numbered from 0 to 5 in a descending order. The top two priority queues adopt PQ scheduling

and the other four queues of lower priority employ Weighted Round Robin (WRR) scheduling.

For details of the mapping between the DSCP values and the IP port queues, refer to

Differentiated Service in Transmission Resource Managementdocument.

3.5 IP RAN VLAN

Virtual Local Area Network (VLAN) enhances the IP transport security. Besides, VLAN

provides the priority service and isolates different users.

3.5.1 Ensuring Security

Compared with the TDM network, the IP network has relatively low security. VLAN

combined with Virtual Private Network (VPN), however, ensures the IP transport security.

Figure 3-18 shows the VLAN and VPN implementation. The security of VLANs is

implemented at the NodeB and the RNC, and that of the VPNs is implemented by external

equipment.

Figure 3-18IP network security



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3.5.2 Providing Priority Service

Figure 3-19 shows a typical example of the VLAN solution on the VLAN on the Iub interface.

In this solution, the Multi-Service Transmission Platform (MSTP) network provides two

Ethernets carried on two Virtual Channel (VC) trunks, respectively.

l One Ethernet is a private network for the real-time services of multiple NodeBs withoutthe influence of other customers. This Ethernet is used to carry services of high priority.

l The other Ethernet is a public network for the non-real-time services of multiple NodeBs

and can be shared with other customers. The services are prone to the influence of othercustomers. Thus, this Ethernet is used to carry services of low priority.

Figure 3-19Typical solution of the VLAN on Iub

Red line: private network

Blue line: public network

Black line: connection between the routers

The VLANID Flag parameter indicates whether VLAN is enabled or not. The NodeB and the

RNC identify the service QoS through Vlan priority in the VLAN tag. Each NodeB or the

RNC provides an Ethernet port to connect to the MSTP network. The MSTP transmits the

Ethernet data to either of the VC trunks according to Vlan priority in the VLAN tag. Each

VC trunk supports up to two QoS classes. In the same VC trunk, the data of different NodeBs

is identified by different VLAN ID parameters.

The VLAN tag contains a 2-byte Tag Protocol Identifier (TPID) and a 2-byte Tag Control

Information (TCI).

l TPID is defined by the IEEE and is used to indicate that the frame is attached with an802.1Q tag. VLAN TPID has a fixed value 0x8100.

l TCI contains the frame control information and consists of the following items:

Priority: a 3-bit field that indicates the frame priority. The eight values, from 0 to 7,represent eight priorities. The priority field is defined in the IEEE 802.1Q protocol.

Canonical Format Indicator (CFI): a 1-bit field. The value 0 indicates the canonical

format and 1 indicates the non-canonical format. CFI specifies the bit sequence of the

address contained in the encapsulated frame in the token ring or source route FDDImedia access method.



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VLAN Identifier (VLAN ID): a 12-bit field that indicates the VLAN ID. It represents

4096 IDs. The frame, which complies with 802.1Q, contains this field and indicateswhich VLAN the frame belongs to.

The NodeB attaches VLAN tags to the frames that are sent from the Ethernet port, but doesnot attach VLAN tags to the frames that are received from the Ethernet port.

When the NodeB supports the VLAN, it attaches diverse tags to different traffic flows to

enable the traffic flow transmission in different VLAN channels.

The parameters on the NodeB side are as follows:

l Traffic Type

l User Data Service Priority

l Insert VLAN Tag

l Vlan Id

l Vlan priority

On the RNC side, the NodeB detection function can be started through the MML command STR

NODEBDETECT in order to periodically send the VLAN IDs to the NodeBs. By this means, when anew NodeB is set up or a NodeB recovers from the fault, the NodeB can automatically obtain its VLANID from the RNC.

3.6 IP RAN FP-MuxFrame Protocol Multiplexing (FP-Mux) encapsulates multiple small FP PDU frames (also

called subframes) into a UDP package, thus improving the transport efficiency. FP-Mux is

only applicable to the user plane data on the Iub interface based on UDP/IP.

Figure 3-20 shows the UDP/IP package format when FP-Mux is applied.

Figure 3-20FP-Mux UDP/IP package format

To enable FP-Mux, the FPMUX flag parameter has to be set to YES. Max subframe length

indicates the maximum length of the subframe. Maximum Frame Length indicates the



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maximum length of the frame of the FP-Mux UPD/IP package. The UDP package frame is

sent out once the time set by FPTIME expires.

FP-Mux is applicable to frames with the same priority, that is, frames of the same DSCP value.

3.7 IP RAN Header CompressionHeader compression is used to reduce protocol header overhead of point-to-point links and to

improve bandwidth efficiency.

The RNC and the NodeB support the following three header compression methods:

l Address and Control Field Compression (ACFC)

l Protocol Field Compression (PFC)

l

IP Header Compression (IPHC)

3.7.1 ACFC

ACFC, which complies with RFC 1661, is used to compress the address and control fields of

PPP protocol. These fields usually contain constant values for PPP links. It is unnecessary to

transport the whole fields every time. If ACFC passes the negotiation during the PPP Link

Control Protocol (LCP), the address and control fields (0xFF03) of subsequent packets can be

compressed.

3.7.2 PFC

PFC, which complies with RFC 1661, is used to compress the protocol field of PPP. PFC can

compress the 2-byte protocol field into a 1-byte one.

The compression complies with the ISO3309 extension mechanism, that is, a binary 0 in the

Least Significant Bit (LSB) indicates that the protocol field contains two bytes, and the other

byte follows this byte. And a binary 1 in the LSB indicates that the protocol field contains one

byte, and this byte is the last one. The majority of packets are compressible, because the

protocol fields assigned are usually less than 256.

3.7.3 IPHC

IPHC, which complies with RFC 2507 and RFC 3544, is used to compress the IP/UDP header

of PPP links. IPHC improves bandwidth efficiency in the following two ways:

l The unchanged header fields in packet (IP/UDP) headers are not carried by each packet.

l The header fields that vary with specified modes are replaced with fewer bits.

The header context is established on both ends of a link when packets with complete headers

are sent occasionally. Thus the compressed packets can retrieve their original headers

according to the context and the changed fields.

l The parameter on the RNC side is Head compress.

l The parameter on the NodeB side is IP Header Compress.



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3.8 IP RAN RedundancyIP RAN Redundancy discusses the redundancy mechanism on the RNC side. The redundancy

of IP RAN helps to improve the reliability of IP transport. On the NodeB side, for distributed

NodeBs, the interconnection of two BBUs can enhance the baseband processing capability but

cannot support the transmission backup.

3.8.1 Single-Homing Layer 3 Networking

In the single-homing layer 3 networking, the FG2a or GOUa board of the RNC serves as the

interface board and supports board backup and FE/GE port backup.

Figure 3-21 shows the single-homing layer 3 networking. The FE/GE ports on the RNC serve

the IP transport.

Figure 3-21Single-homing layer 3 networking

In this networking mode, the FE/GE ports of the RNC are configured for backup. The activeand standby FE/GE ports of the RNC are connected to the Provider Edge (PE), which are

further connected to the IP network. The active and standby FE/GE ports of the RNC share

one IP address, IP 1-0. The PE configures the active and standby ports of the RNC in one

VLAN and uses one interface IP address of the VLAN, IP 1-1.

The GE optical ports on the GOUa board are applicable when the RNC is far away from the PE, and the

FE/GE electrical ports on the FG2a board are applicable when the distance between the RNC and the PEis within 100 m.

3.8.2 Dual-HomingLayer 3 Networking

In the dual-homing layer 3 networking, the FG2a or GOUa board of the RNC serves as the

interface board and supports board backup and FE/GE port backup.

Figure 3-22 shows the dual-homing layer 3 networking. The FE/GE ports on the RNC serve

the IP transport.



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Figure 3-22Dual-homing layer 3 networking

In this networking mode, the FE/GE ports of the RNC are configured for backup. The activeand standby FE/GE ports of the RNC are connected to two PEs, which are further connectedto the IP network. Complying with the Virtual Router Redundancy Protocol (VRRP), the two

PEs provide redundancy-based protection for the data transmitted from the RNC. One PE

connects to the other through two GE ports. Link Aggregation (LAG) is applied to the

interconnection links between the PEs to increase the bandwidth and reliability of the links.

The active and standby FE/GE ports of the RNC share one IP address, IP 1-0. The PEs

configure the active and standby ports of the RNC in one VLAN and use one virtual VRRP IP

address, IP 1-1.

The GE optical ports on the GOUa board are applicable when the RNC is far away from the PE, and theFE/GE electrical ports on the FG2a board are applicable when the distance between the RNC and the PE

is within 100 m.

3.8.3 Advantages and Disadvantages of the Networking

Single-homing layer 3 networking provides redundancy-based protection for FE/GE links.

The single PE saves the networking costs, but cannot provide PE-level protection.

Dual-homing layer 3 networking provides redundancy-based protection not only for FE/GE

links, but also for PE devices. But the dual PEs have high networking costs.

3.8.4 Configuration on the RNC Side

To support the backup of the interface board, the Backup parameter has to be set to YES.

The parameters on the RNC side are as follows:

l Board type

l Backup

When the interface board is set to the backup mode, run the ADD ETHREDPORT command

to set the backup mode of the associated ports.

The parameter involved is Port No..

For detailed information about board redundancy and port redundancy, see RNC Parts Reliability in the

RNC Product Description.



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3.8.5 Fault Detection

In addition to the UP/DOWN detection performed at the physical link layer, the fault

detection between the RNC and the Provider Edge (PE) involves the Bidirectional Forwarding

Detection (BFD) and Address Resolution Protocol (ARP) detection. The BFD or ARPdetection are applied on the layer 3 (L3) detection, which can also detect other faults, such as

soft transfer. When the BFD or ARP detection finds a fault, the switchover between FE/GE

ports will be triggered. The application of the BFD or ARP detection can increase the fault

detection rate and enhance the reliability. The BFD is preferred since it has a quick and

bidirectional detection.

l The ARP detection is used only when the peer equipment does not support the BFD, because theARP detection is unidirectional.

l The ARP message is a broadcast message; therefore, if there is a relatively large L2 broadcastdomain between the RNC and the L3 equipment, a broadcast storm may easily occur. But if theRNC and the L3 equipment are directly connected, a broadcast storm never occurs.

The following tables describe the parameters of the Fault Detection:

l Gateway IP address


l Backup port mask


l Check type

l Port work mode

l Min interval of BFD packet send [ms]

l Min interval of BFD packet receive [ms]

l detect multiplier of BFD packet

3.9 IP RAN Load SharingIP RAN load sharing improves the transport efficiency of IP RAN. Load sharing between

FE/GE ports of the RNC is applicable to layer 3 networking between the RNC and other NEs,

instead of layer 2 networking.

3.9.1 Load Sharing Layer 3 Networking

The RNC supports load sharing between FE/GE ports that are located either on the same

board or on the active and standby boards. The RNC supports load sharing between up tothree FE/GE ports.

Figure 3-23 shows the load sharing layer 3 networking of IP RAN. If there are two ports for

load sharing, they are located on the active and standby boards.



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Figure 3-23Load sharing layer 3 networking

In this scenario, the FG2a or GOUa board of the RNC serves as the interface board, and

supports board backup and FE/GE port apart.

The two FE/GE ports on the active and standby boards are configured with IP addresses of

different network segments, IP 1-0 and IP 2-0. The PE configures the corresponding IP

addresses, IP 1-1 and IP 2-1. The data to the destination IP address is shared by the two routes.

The load sharing ports on the RNC can be connected to one PE or two different PEs.

3.9.2 Advantage and Disadvantage of the Networking

In the load sharing layer 3 networking, the data traffic is shared by the ports to avoid the

occasion when some ports are busy while others are idle, thus improving the transmission

efficiency. This network solution, however, does not provide redundancy for data transmission.

A port failure will lead to the decline of transmission capacity.

3.9.3 Configuration on the RNC SideTo support the load sharing between the ports located on the active and standby boards, the

Backup parameter should be set to NO. For detailed information about the parameters, see

3.8 IP RAN Redundancy.

For details about board redundancy, port redundancy, and port load sharing, refers toRNC Parts

Reliability in theRNC Product Description

3.10 IP RAN DHCP

The Dynamic Host Configuration Protocol (DHCP) dynamically provides configurationparameters for network terminals. The DHCP can automatically allocate the network address

and set up the OM channel for IP RAN.

The DHCP has the following characteristics:

l Working in the Client/Server mode. When receiving the request from a client, the server

provides parameters such as the IP address, gateway address, DNS server address for theclient.

l Simplifying IP address management.

l Enabling centralized IP address management.

l Complying with RFC 2131 and RFC 2132.



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In the DHCP procedure, the RNC works as the DHCP server and the NodeBs work as DHCP

clients. The NodeB can automatically obtain the IP address to set up the OM channel. Figure

3-24 shows the DHCP procedure.

Figure 3-24DHCP procedure

The four basic phases of the DHCP procedure are as follows:

Step 1 DHCP discovery: The NodeB broadcasts DHCPDISCOVER packets to find the RNC.

Step 2 DHCP offer: The RNC sends the configuration information such as IP addresses to the NodeBthrough DHCPOFFER packets.

Step 3 DHCP selection: The NodeB selects an IP address from the DHCPOFFER packets and thenresponds by broadcasting DHCPREQUEST packets.

Step 4 DHCP acknowledgement: The RNC responds by sending DHCPACK packets to the NodeB.

The parameters on the RNC side are as follows:

l The First Serial Number

l The Second Serial Number

l NodeB IP_TRANS IP address

l NodeB ATM_TRANS IP address

----End

3.11 IP RAN Transport CapabilitiesIP RAN Transport Capabilities provides information about the transport capabilities related to

the IP RAN.

3.11.1 RNC IP Transport CapabilitiesTable 3-7 describes the IP transport capabilities at the RNC.

Table 3-7IP transport capabilities at the RNC

Item Sub-Item Description

Board At most 14 per RBS and 10 per RSSPhysical interfaces

FE port 4 FEs per sub-board and 2 sub-boards per

board



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Item Sub-Item Description

GE port 1 GE per sub-board and 2 sub-boards per

board

E1/T1 32 E1s/T1s per sub-board and 1

sub-board per board

IP version IP protocol version IPv4

MAC/FE or MAC/GE Supported

PPP/E1 Supported

PPPmux/E1 Supported

ML PPP/E1 Supported

MC PPP/E1 Supported

PPP/E1/SDH Supported

PPPmux/E1/SDH Supported

ML PPP/E1/SDH Supported

MC PPP/E1/SDH Supported

PPP/SDH Supported

Layer 2 protocols

PPPmux/SDH Supported

QoS DiffServ Supported

Header compression IP Header Compressionover PPP (RFC 2507)

Supported (on E1)

Port backup Supported (FG2a/GOUa/POUa/UOIa

inter-board level)

Reliability

Board backup Supported (all the interface boards)

NOTE:RBS = RNC Business Subrack, RSS = RNC Switch Subrack, IPv4 = Internet Protocol version 4, MAC =Media Access Control, PPPMux = PPP Multiplexing, ML PPP = Multi-Link PPP, MC PPP = Multi-ClassPPP, SDH = Synchronous Digital Hierarchy, QoS = Quality of Service, DiffServ = DifferentiatedServices

3.11.2 BBU IP Transport Capabilities

Table 3-8 describes the IP transport capabilities at the BBU.

Table 3-8IP transport capabilities at the BBU (DBS3800 and iDBS3800)

Item Quantity/Location Flow Protocol

E1/T1 8 per BBU PPP



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FE 2 per BBU MAC

IPoA client 1 per BBU ATM

Maintenance flow on the Iub

interface

1 per BBU Low TCP

Traffic flow Several per BBU High UDP

Signaling flow Several per BBU Medium SCTP

IP route flow Several per BBU High IP

NOTE:IPoA = IP over ATM, TCP = Transfer Control Protocol, UDP = User Datagram Protocol, SCTP = StreamControl Transmission Protocol

Table 3-9 describes the IP transport capabilities at the BBU (DBS3900 and iDBS3900).

Table 3-9IP transport capabilities abilities at the BBU (DBS3900 and iDBS3900)


E1/T1 4 per WMPT, 8 per UTRP PPP

FE 1 optical and 1 electrical per WMPT MAC

IPoA client 1 per BBU ATM

Maintenance flow onthe Iub interface

1 per BBU Low TCP

Traffic flow Several per BBU High UDP

Signaling flow Several per BBU Medium SCTP

IP route flow Several per BBU High IP

NOTE:

IPoA = IP over ATM, TCP = Transfer Control Protocol, UDP = User Datagram Protocol, SCTP =Stream Control Transmission Protocol

3.11.3 Macro NodeB IP Transport Capabilities

Table 3-10 and Table 3-11show the IP transport capabilities at the macro NodeB.

Table 3-10IP transport capabilities at the macro NodeB (BTS3812E/BTS3812AE)


E1/T1 8 per interface board PPP

FE 2 per interface board MAC



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IPoA client Several per interface board ATM

Maintenance flow on the Iubinterface

1 per BBU Low TCP

Traffic flow Several per interface board High UDP

Signaling flow Several per interface board Medium SCTP

IP route flow Several per interface board

(inter-board flow supported)

High IP

Table 3-11IP transport capabilities at the macro NodeB (BTS3900/BTS900A)


E1/T1 4 per WMPT, 8 per UTRP PPP

FE 1 optical and 1 electrical per

WMPT

MAC

IPoA client 1 per interface board ATM

Maintenance flow on the Iub

interface

1 per BBU Low TCP

Traffic flow Several per interface board High UDP

Signaling flow Several per interface board Medium SCTP

IP route flow Several per interface board

(inter-board flow supported)

High IP



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4-1

4 IP RAN ParametersThis chapter provides information on the effective level and configuration of the parameters

related to IP RAN.

Table 4-1 lists the parameters related to IP RAN.

Table 4-1Parameters related to IP RAN

Parameter Name Parameter ID Effective Level Configurationon...

IUB trans bearer type TnlBearerTypeNodeB(ADD

NODEB)RNC

IP Trans Apart IndIPTRANSAPARTI

ND

NodeB(ADD

NODEB)RNC

Adjacent Node Type NODETAdjacent Node(ADD

ADJNODE)RNC

Transport Type TRANSTAdjacent Node(ADD

ADJNODE)RNC

Bearing Mode MODENodeB(SET

E1T1BEAR)NodeB

Local IP address IPADDRIP Path(ADD

IPPATH)RNC

Peer IP address

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