Copyright © 2004 Juniper Networks, Inc. 1 SEEREN2 Summer School Heraklion, Sept 25 th Routing...

Copyright © 2004 Juniper Networks, Inc. www.juniper.net 1

SEEREN2 Summer SchoolHeraklion, Sept 25th

Routing Issues: QoS/CoS

Jean-Marc UzéLiaison Research & Education, EMEA

[email protected]

2Copyright © 2004 Juniper Networks, Inc. www.juniper.net

Agenda: QoS/CoS Workshop

Module 1: Overview of QoS/CoS Module 2: JUNOS CoS implementation (J/M/T-

Series) Module 3: Introduction to JUNOS CLI Module 4: GEANT2 QoS services

ImplementationThe content of this module is

courtesy of Dante (http://www.dante.net)

http://www.dante.net/nep/geantqos/http://www.dante.net/tf-ngn/activities.html


Module 4:GEANT2 QoS services implementation

GÉANT Network and Services Premium IP Less than Best Effort Queuing on GÉANT and status Router Configuration Premium IP Management


10 Gb/s IP/MPLS backbone with Juniper T640s, M160s, M40s

4 x 10 Gb/s to North America

Dark fiber and WDM optical technology

Connecting 34 European Countries and 30 National R&E Networks

European connectivity to over 3000 R&E institutions

Advanced Services: IPv6 Premium IP Multicast v4 + v6 Best Effort Less Than Best Effort Layer 2 VPN

GEANT2 / Dante


Global Connectivity


IP QoS Services on GÉANT

Premium IP upper-bounded one-way delay upper-bounded IPDV negligible packet loss guaranteed capacity

Less than Best Effort class of traffic using the un-utilised Best Effort

and higher classes of service bandwidth

http://www.geant.net/server/show/nav.00700a009


AGENDA



Premium IP Model

End-to-end service across multiple management domains using diffserv, ATM CBR or over-provisioning(!) packet tagged DSCP 46 (EF - 101110) destination aware service packet with other DSCP are left untouched (packets

from other service) Premium IP bandwidth limited to 10% of the link

capacity can cope with 20% in case of circuit failure


GEANT and IP Premium Service

Source: http://www.dante.net/sequin


Premium IP on GEANT

Protection of authorised Premium IP traffic under normal circumstances, the Premium IP traffic

of a circuit is limited to 10% of the circuit capacity 20% in case of another circuit failure

bullet-proof all the GÉANT accesses against unauthorised Premium IP traffic (tagged DSCP 46) on all the ingress interfaces

if DSCP 46 packet arrives on GÉANT and part of an unauthorised flow: classify the packet into the Best Effort queue and remark it as Best Effort (DSCP 0)

if DSCP 46 packet arrives on GÉANT and is part of an authorised flow: check against policer according capacity requested in the SLA (in-profile accepted, out-of-profile dropped)


Premium IP on GEANT Protection of authorised Premium IP traffic [cont]

per next AS rate-limitation (implemented by Juniper for GÉANT) can also do source-destination IP addresses when NREN don’t

do it. (NREN = National Research & Education Network, a Dante customer network directly connected to GEANT)

Trust the Premium IP traffic received from a GÉANT backbone interface. Traffic checked at the GÉANT ingresses.

Configure queuing mechanism on the backbone and access interfaces. strict-high priority is configured to the Premium IP queue.

Don’t forget that the amount of Premium traffic expected in the Premium IP queue is 10% of the link capacity (service over-provisioned by a factor 9); this is assured by ingress policing.

90% for the BE and 5% for the network control (and 5% for LBE)


Jitter distribution in VBR traffic - BE & Premium IP

0%

10%

20%

30%

40%

50%

60%

70%

0.0

0

0.1

9

0.3

8

0.5

6

0.7

5

0.9

4

1.1

3

1.3

1

1.5

0

1.6

9

1.8

8

2.0

7

2.2

5

2.4

4

2.6

3

2.8

2

3.0

1

3.1

9

3.3

8

3.5

7

3.7

6

Premium IP BE jitter[ms]

pe

rce

nta

ge

of

pa

ck

ets

Avg. jitter vs. packet size - BE & Premium IP

0

2

4

6

8

10

12

14

Premium IP BE

avg

. jit

ter

[ms]

packet size [bytes]

Test result end-to-end IP Premium


AGENDA



Less than Best Effort

Class of traffic using the un-utilised Best effort and higher classes of service bandwidth in case of competition for resources, the LBE traffic will de

discarded before any Best-Effort or higher classes of traffic.

use the DSCP 8 (001000) - same as Internet2 scavenger service.

Congestion on an interface due to LBE should be transparent to the BE or higher classes of

services no BE or higher classes of services packet loss


Less than Best Effort

No end-to-end guarantees no metric needed to quantitatively describe the service

Can be supported on one interface anywhere else, the LBE tagging should be passed

transparently.

Application scenarios mirroring, test traffic, some GRID data transfers, network

backups, protection of research traffic from student dormitory one.


LBE Queuing Technique

For algorithm with bandwidth shared assignment, as Weighted Wound Robin and Weighted Fair Queuing, a very small bandwidth share is allocated to the LBE queue. Typically between 0% and 5%


LBE: Measurement with congestion

One-way delay Increase of LBE maximum one-way delay of 1.5ms Increase of BE maximum one-way delay of 400µs


Normal Traffic

Normal Traffic +Less Than Best Effort2.0 Gbit/s

Normal Traffic +

Radio Astronomy Data500 Mbit/s

Normal Traffic +

Radio Astronomy Data +Less Than Best Effort2.0 Gbit/s

LBE live test:ER2002 Demo - VLBI - dataGRID


AGENDA



Queuing Technique

WRR - Juniper M-series

Weight Assure the queue to be given a minimum amount of

bandwidth proportional to the weight. Priority

queue with high priority are served before the low priority

allow the BE (and other high priority queues) to be served first until empty before serving the LBE one.

WRED is used to limit the queuing delay in case of congestion use to protect one class of traffic over the other within

a queue.


DSCP/ToS Values used by GEANT

Service DSCP value ToS value Juniper alias ToS (hex) DSCP-ToS binary

Premium IP 46 184 ef B8 101110 - 101110xx

LBE 8 32 cs1 20 001000 - 001000xx

DWS 32 128 cs4 80 100000 - 100000xx

Network control 1

48 192 cs6 C0 110000 - 110000xx

Network control 2

56 224 cs7 E0 111000 - 111000xx

The DSCP/ToS values used in GÉANT to classify the traffic of the different QoS classes are shown in the table below. In addition to the three service classes offered to transiting traffic there is a DWS (IP commodity service) and a Network Control class, which are traffic classes used internally to the GÉANT network.


Juniper Networks and CoS ServicesGEANT with IP Premium + LBE Service

Junos CoS features include policing, (strict) priority queuing, weighted round robin (WRR), precedence/DSCP field rewrite, and random early drop RED.

On a Juniper M-series Router each port has 4 Queues Weighted Round Robin Percentages can be set for each Queue

New generation Q-PICs offers multiples queues per logical interfaces (Ethernet VLAN, ATM PVC, etc.)

WRWRRR

Source: http://www.dante.net/nep/geantqos/ and http://www.dante.net/tf-ngn/activities.html

Queue FC LP Service DSCP Weight Priority Buffer low Best Effort / 0 BE high DWS 32

90% Low 50%

low Premium IP 46 1 EF high / /

N/A Strict-high

15%

low Less than BE 8 2 LBE high Retag to BE 0

5% low 30%

low Network control 48 3 NC high Network control 56

5% high 5%


QoS Configuration on GEANT The configuration has completed on most of

the GEANT routers allowing Premium IP, BE and LBE to co-exist.

The routers where the three services have been enable are represented as green on the following map.

The routers coloured yellow are Juniper routers where “old” FPCs have been re-used from TEN-155 (1999) These old FPC’s that do not allow for the full functionality of QoS.

As such BE is not ideally protected by LBE and the bandwidth is effectively shared. Premium IP only is supported.


Current QoS Configuration on GEANT


AGENDA



Router Configuration

Each router in the GÉANT network contains certain QoS building blocks in order to configure Per Hop Behaviors (PHB). The configuration shown here is taken from a Juniper M160 router with JUNOS 5.7 and with E-FPC (enhanced FPCs) and SDH interfaces.

Classifiers, schedulers and rewrite rules can be associated to each interface. In GÉANT two types of interface configurations are used for QoS a backbone interface an access interface (i.e. the interface where the traffic

from an NREN is entering GÉANT)


DSCP and ToS Values

Type of Service field illustration

Illustration of DSCP Type of Service field

configuration

Service DSCP value ToS value Juniper alias ToS (hex) DSCP-ToS binary

Premium IP 46 184 ef B8 101110 - 101110xx

LBE 8 32 cs1 20 001000 - 001000xx

DWS 32 128 cs4 80 100000 - 100000xx

Network control 1 48 192 cs6 C0 110000 - 110000xx

Network control 2 56 224 cs7 E0 111000 - 111000xx


Router Interfaces

Backbone interface

so-7/0/0 { scheduler-map MAP-BASIC; unit 0 { classifiers { dscp backbone-classifier; } rewrite-rules { dscp basic-rewrite-rules; } }}

Access interface

so-0/2/3 { scheduler-map MAP-BASIC; unit 0 { classifiers { dscp access-classifier; } rewrite-rules { dscp basic-rewrite-rules; } }}

In addition, the access interface may contain filters in order to classify and police Premium IP traffic.The following configurations apply to all (access and backbone) interfaces.


Drop Profiles Drop profile define the parameters used by

the Random Early Detection (RED) mechanism that MAY be used in a queue

dws-drop-profile { fill-level 35 drop-probability 10; fill-level 40 drop-probability 100;}be-drop-profile { fill-level 15 drop-probability 30; fill-level 19 drop-probability 50; fill-level 24 drop-probability 70; fill-level 30 drop-probability 100;}less-than-be-drop-profile { fill-level 25 drop-probability 30; fill-level 30 drop-probability 50; fill-level 40 drop-probability 70; fill-level 50 drop-probability 100;}


Queues and Schedulers1. Associate a name with each queue

Note: a queue is sometimes also called a forwarding class

forwarding-classes { queue 0 best-effort; queue 1 expedited-forwarding; queue 2 less-than-best-effort; queue 3 network-control;}

The Premium IP traffic is classified into the expedited-forwarding queue. The naming of the queues is performed once and applies to all interfaces of the router.


Queues and Schedulers1. Define scheduler configurations

scheduler weight, queue size and priority as set at the GÉANT router for each queue:sch-best-effort { transmit-rate percent 90; buffer-size percent 50; priority low;}sch-expedited-forwarding { buffer-size percent 15; priority strict-high;}sch-less-than-best-effort { transmit-rate percent 5; buffer-size percent 30; priority low; drop-profile-map loss-priority low protocol any drop-profile less-than-be-drop-profile; drop-profile-map loss-priority high protocol any drop-profile be-drop-profile;}sch-network-ctrl { transmit-rate percent 5; buffer-size percent 5; priority high;}


Queues and Schedulers3. Associate a scheduler with a queue (FC)

The main advantage of the scheduler-map is that it can be applied to more than one interface.

MAP-BASIC { forwarding-class best-effort scheduler sch-best-effort; forwarding-class expedited-forwarding scheduler sch-expedited-forwarding; forwarding-class less-than-best-effort scheduler sch-less-than-best-effort; forwarding-class network-control scheduler sch-network-ctrl;}


Classification The classifier is a functional block located at the input interface that sets

three internal bits for each IP packet Two bits that select the output-queue. There are four output queues, also

called forwarding-classes, per port. One bit to indicate the loss-priority, the packets classified in an output-queue

can have two different values of loss-priority (low or high). Note that it is also possible to classify packets by means of an input

filter.

Backbone Classifierdscp backbone-classifier { import default; forwarding-class best-effort { loss-priority low code-points [ af11 af12 af13 ]; loss-priority high code-points cs4; } forwarding-class less-than-best-effort { loss-priority low code-points cs1; }}

Access Classifierdscp access-classifier { import default; forwarding-class best-effort { loss-priority low code-points [ af11 af12 af13 ]; } forwarding-class less-than-best-effort { loss-priority low code-points cs1; loss-priority high code-points [ ef cs4 ]; }


Marking The marking of packets with a DSCP value is the last

QoS action performed before the transmission of the packet (hence after firewall filter evaluation)

dscp basic-rewrite-rules { forwarding-class best-effort { loss-priority high code-point cs4; } forwarding-class expedited-forwarding { loss-priority low code-point ef; } forwarding-class network-control { loss-priority low code-point nc1; loss-priority high code-point nc2; } forwarding-class less-than-best-effort { loss-priority high code-point be; loss-priority low code-point cs1; }}

ServiceIncoming DSCP

valueNew DSCP

value

Authorised Premium IP 46 46/drop

Un-authorised Premium IP

46 0/5

DWS 32 0

LBE 8 8

Network Control 48/56 48

Best Effort other values Unchanged


AGENDA



Useful Tool Feature of the NANOG traceroute to discover

the DSCP changes along the path (Simon Leinen from Switch:-)

[root]# ./traceroute -t 184 193.171.2.1 traceroute to 193.171.2.1 (193.171.2.1), 30 hops max, 40 byte packets 1 css7-ATM4-0-0-101-dmsk.man.poznan.pl (150.254.160.62) 1 ms 1 ms 1 ms 2 150.254.163.118 (150.254.163.118) 2 ms 2 ms 2 ms 3 z-pozmanu-oc3.poznan-gw.pol34.pl (212.191.127.49) 2 ms 2 ms 2 ms 4 pol-34.pl1.pl.geant.net (62.40.103.109) 2 ms 2 ms 2 ms 5 pl.cz1.cz.geant.net (62.40.96.45) 22 ms (TOS=0!) 22 ms 22 ms 6 cz.de1.de.geant.net (62.40.96.38) 30 ms 30 ms 30 ms 7 de1-1.de2.de.geant.net (62.40.96.130) 30 ms 30 ms 31 ms 8 de.at1.at.geant.net (62.40.96.5) 43 ms 43 ms 43 ms 9 aconet-gw.at1.at.geant.net (62.40.103.2) 43 ms 43 ms 43 ms 10 193.171.2.1 (193.171.2.1) 45 ms * 45 ms


Need for Automation

Service management was done manually Service set up, maintenance and

termination was done by phone calls and emails

Considerable manual effort required Complexity in keeping track of:

Path information Current and future reservations Premium IP utilisation levels Changes in network topology

Multi-party communication


System Architecture

Java web-based architecture Using Apache 1.3 web server, Tomcat

servlet container & MySQL Database


Premium IP Reservation Tool Features (1)

Authentication & Authorisation Path Finder

Find shortest path between two end pointsDynamic based upon configured IS-IS cost

Utilisation Monitoring Check Premium IP reservation levels on

each intermediate link along the path Take into account all active reservation

during the given time period Display the available Premium IP capacity


Premium IP Reservation Tool Features (2)

Reservation Management View, Request, Modify, Cancel Based upon available Premium IP capacity

Contact managementIP Address management

Automated email notification to User, DANTE - Premium IP team, NOC upon Reservation Request, Modification,

Cancellation Router Configuration update (script) Others: IS-IS cost, Reports, Archival,

System Administration...



Thank you

Jean-Marc UzéLiaison Research & Education, EMEA

[email protected]

Mobile: +3361543251231 Place Ronde, 92986 Paris-La-Defense, France

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