View
221
Download
0
Category
Preview:
Citation preview
Nicolas Simar – DANTE - Sequin: Premium IP
SEQUIN Premium IP
Nicolas Simar – DANTE - Sequin: Premium IP
Project info• SEQUIN - SErvice QUality across Independently
managed Networks (IST-1999-20841)
• Duration 18 months (Nov 2000...Apr 2002)
• Partners:
• Project Web site: http://www.dante.net/sequin
• Technical Web site: http://www.switch.ch/lan/sequin
DANTE, DFN, GARR, GRNET, PSNC, RENATER, SWITCH, UKERNA
Nicolas Simar – DANTE - Sequin: Premium IP
Overview
• SEQUIN has defined and implemented an end-to-end approach to Quality of Service (QoS), operating across multiple management domains and exploiting a combination of IP and ATM technology
• The project has specified the implementation architecture for the Premium IP service, which aims at offering the equivalent of an end-to-end virtual leased line service at the IP layer across multiple domains.
• The architecture is targeted at the GÉANT (The pan-European Gigabit Research Network) and is applicable to each connected National Research and Education Network (NREN) across Europe and local DiffServ domains
Nicolas Simar – DANTE - Sequin: Premium IP
Definition of QoS
• Work of WP2 ->D2.1• Top-down approach
– Interview with international user groups on their requirements
• Bottom-up – Network performance parameters that may be
influenced by configuration of equipment
Nicolas Simar – DANTE - Sequin: Premium IP
QoS parameters
• From users’ requirements and technical considerations :– One-way delay (OWD)
– IP packet delay variation (IPDV)
– Available bandwidth
– One-way packet loss (OWPL)
• The set is common to IETF and ITU-T
• Naming and definitions are chosen to be comply to RFC 2330 (Framework for IP Performance metrics) and follow the ongoing IPPM IETF working group work.
Nicolas Simar – DANTE - Sequin: Premium IP
QoS user requirementsQoS service One-way-delay ipdv packet loss bandwidth
Best effort wide wide medium wideVery good( Premium IP ) medium very small very small
according toSLA
PrioritisedBandwidth (IP+) medium medium medium
according toSLA
Guaranteedbandwidth
medium medium very small single value
One-way-delay IPDV Packet loss bandwidthBest effort Unspecified Unspecified < 5% Unspecified
Premium IPdistance delay
+ 50 ms< 25 ms negligible
according toSLA
IP+distance delay
+100 ms <25-50 ms < 2%
according toSLA
(from user’s questionnaire)
Nicolas Simar – DANTE - Sequin: Premium IP
Premium IP Specification
• Differentiated Services Architecture and use the expedited forwarding per hop behavior (EF PHB) • Interface definition between domains that behaves as an EF PHB• Do not starve best effort traffic (limited percentage of link capacity devoted to Premium IP)• Initial provisioning structure: static, no dynamic signaling• IETF IPPM QoS parameters measurement framework• QoS parameters monitoring system is a key element
Nicolas Simar – DANTE - Sequin: Premium IP
Premium IP Service
ImplementationBasic principles
minimize number of actions per node do not use a signaling protocol modular approach that allows different
implementation schemes at every hop or domain and allows domains to join the service when ready
Do not try to solve the most general problem, but rather develop a model that can be implemented in short time using available tools
Keep it simple
Nicolas Simar – DANTE - Sequin: Premium IP
Simplifying the actions for each node
- monitoring and accounting- QoS rules propagation
- congestion control
- admission control and classification
- scheduling
In principle, each node might perform an awful lot of tasks:
- marking - policing
- shaping
Nicolas Simar – DANTE - Sequin: Premium IP
Use the information in the IP header:
- IP source and destination (prefixes) as near to the source as possible
- the DSCP (or IP precedence equivalent value) along the path
- perform an optional, suggested, admission control based on AS source and destination at inter-domain links (safety measure)
- rules might be based on additional parameters, such as time-of-day
Admission control
Nicolas Simar – DANTE - Sequin: Premium IP
The consequences are:- allowing the computation of total requested Premium IP capacity at each network node in the default case (and for main backup cases too)
- short access list near users’ premise (few users)
- simple control at backbones (IP addresses are not propagated)
- choosing destination aware service (next slide)
Admission control (continued)
Nicolas Simar – DANTE - Sequin: Premium IP
AB
C
D
E
F
Guser 1 user 2
user 5
user 4
user 3
user IN (SLS) OUT (SLS) IN (real) OUT (real)1 10 10 40 02 10 10 0 103 10 10 0 104 10 10 0 105 10 10 0 10
Destination AwareVs destination Unaware
Admission control (continued)
Nicolas Simar – DANTE - Sequin: Premium IP
Examining the tasks for each node
- monitoring and accounting- QoS rules propagation
- congestion control
- admission control and classification
- scheduling
In principle, each node might perform an awful lot of tasks:
- marking - policing
- shaping
always
Nicolas Simar – DANTE - Sequin: Premium IP
- Mark each “EF” legal packet at first classification point- Use the same DSCP value on all domains (decimal 46 [RFC 2474] to have interoperability with ToS only capable hardware) - strongly suggested -- valid DSCP coupled to invalid IP addresses may imply discard to allow easy debugging- packets with other DSCP values are left untouched
Marking is mandatory at the first classification point, remarking is optional.
Marking
Nicolas Simar – DANTE - Sequin: Premium IP
Examining the tasks for each node
- monitoring and accounting- QoS rules propagation
- congestion control
- admission control and classification
- scheduling - marking - policing
- shaping
always
Selectedlocations
Nicolas Simar – DANTE - Sequin: Premium IP
• Microflow policing should be done as close as possible to the source according to agreed (through SLA) Premium IP capacity. This step is mandatory
• Policing will be done using a token bucket. The depth of the token bucket will be two MTU close to the source and increase to 5 or more along the path if additional policing is required
• It is suggested to perform only one additional policing stage at the ingress to GÉANT from an NREN, with a larger aggregated capacity value than the sum of the agreements.
“Avoid unwanted packet loss” is the motto.
Policing
Nicolas Simar – DANTE - Sequin: Premium IP
• The additional policing stage at the ingress to GÉANT from an NREN serves the purpose of protecting Premium IP traffic from misconfiguration/DoS coming from a single source.
• It creates virtual “pipes” for the aggregated Premium flows from each NREN to each other (when needed). The failure of one “pipe” does not influence the others.
Policing (continued)
Nicolas Simar – DANTE - Sequin: Premium IP
L1 L2
N1
N2
N3
CORE
L1, L2 : end user domain (for example LANs)N1, N2, N3 : intermediate transport domains (for example NRENs backbones)CORE : interconnection domain (for example GÉANT) : router/switch
Sample multidomain network
Classification on IP addressesStrict policing
Policing can be avoidedat ingress when receivingfrom a trusted backbone
Classify by DSCPPolice by (AS source,dest)aggregate capacityon all border nodes
Policing not needed
Nicolas Simar – DANTE - Sequin: Premium IP
Examining the tasks for each node
- monitoring and accounting- QoS rules propagation
- congestion control
- admission control and classification
- scheduling - marking - policing
- shaping
always
Selectedlocations
Selectedlocations
always
Nicolas Simar – DANTE - Sequin: Premium IP
Shaping
The sending source is required to shape the traffic it produces.
Shaping can be done by the network close to the user
Shaping inside the sending host itself is the preferred way, shaping by the network will in most case lead to packet losses
TCP
Application
Scheduling
IP
Network Interface
No Packet/Data losses
host
Nicolas Simar – DANTE - Sequin: Premium IP
AB
C
D
E
F
Guser 1 user 2
user 5
user 3
Shaping
Multiple aggregation-separationpoints and link speed changes.
Nicolas Simar – DANTE - Sequin: Premium IP
Examining the tasks for each node
- monitoring and accounting- QoS rules propagation
- congestion control
- admission control and classification
- scheduling - marking - policing
- shaping
always
Selectedlocations
Selectedlocations
always
NODone bysource
notneeded
Selectedlocations
Selectedlocations
Nicolas Simar – DANTE - Sequin: Premium IP
Shape ONLY here Classify (IP pair prefixes)Police - Strict, CapacityMark
Classify (DSCP) High priority queueingon all nodes
Do not police on egressDo not shape
Policing can be avoidedat ingress when receivingfrom a trusted backbone
Police by (AS source,dest)aggregate capacity on all border nodes
Summary
Nicolas Simar – DANTE - Sequin: Premium IP
Grey Areas
Exact configuration of buffering and token bucket depth in routers. As a rule of thumb the token bucket depth can be assumed to be 1.2 * (Diffserv active interfaces on router)
Scalability - the maximum amount of aggregated Premium IP capacity the network can offer- hardware capabilities
Fast provisioning of the service
Widespread availability and tuning of “last mile” (LANs)
Nicolas Simar – DANTE - Sequin: Premium IP
Example (one direction)
Domain 1802.1p VLANOr dedicated wire
Domain 5802.1p VLANOr dedicated wire
Domain 2ATM
Domain 3Backbone
Classification (DSCP)Policing (AS aggregate)
Classification (DSCP)Policing (AS aggregate)
Domain 4
Classification (IP)Policing (strict 2 MTU)Marking - scheduling
Classification (IP)Policing (strict 2 MTU)Marking - scheduling
Classification (DSCP)Scheduling
Classification (DSCP)Scheduling
Dedicated PVCDedicated PVC
Nicolas Simar – DANTE - Sequin: Premium IP
“Proof of Concept”• Initial implementation of the testing methodology by
implementing a “Proof of Concept” test-bed involving user groups
• Goals:– access to a controlled environment composed of a variety of
hardware and underlying technology– functionality verification of each component required to implement
Premium IP
• The set of tests performed included:– laboratory tests for basic router functionality– wide area tests for network calibration (understand the performance
users can expect & the interaction between different network technologies)
– tests involving users to verify the QoS provisioning processes
Nicolas Simar – DANTE - Sequin: Premium IP
H.323 users tests• H.323 users from TF-STREAM Task Force
– TF-STREAM, http://www.terena.info/task-forces/tf-stream/
• Tests– Core network (GÉANT): 10Gbit/s & 2.5 Gbit/s POS and Juniper routers.
– 4 high (2.5 Gbit/s POS) and lower (2x155Mbit/s ATM access) speed national networks connecting six testing locations
– Traffic tests with measurement tools with/without Premium IP enabled– Objective and subjective quality assessments of H.323 videoconferencing
Nicolas Simar – DANTE - Sequin: Premium IP
H.323 tests topology
Nicolas Simar – DANTE - Sequin: Premium IP
Test scenarios• End-to-end setup, between each pair of the participants
• Videoconference initiated – users assessment of audio and video quality
• ICMP Ping tool was used to measure end-to-end RTT
• The videoconference session was terminated
• Use of RUDE/CRUDE tool with traffic pattern imitating videoconference stream in both directions for recording jitter and packet loss
• NETPERF throughput test was used to assess the bandwidth available for Premium IP service
Nicolas Simar – DANTE - Sequin: Premium IP
Test results IIP Premium
Audio SWITCH FOKUS RUS GRNET CINECASWITCH x 3(MCU) 4-5 6 6FOKUS 3.6 x 6 3 6
RUS 3.6 6 x 6 6GRNET 5.4 3(MCU) 5 x 6CINECA 6 6 5 6 x
FROM
IP Premium
Video SWITCH FOKUS RUS GRNET CINECASWITCH x 6(MCU) 5 6 6FOKUS 4.8 x 6 5 6
RUS 4.8 6 x 4 6GRNET 5.4 5(MCU) 5 x 5CINECA 5.4 6 5 5 x
FROM
Nicolas Simar – DANTE - Sequin: Premium IP
Test results IIIP Premium
Bandwidth [10^3 bit/s] SWITCH FOKUS RUS GRNET CINECASWITCH x 3307.87 1909.83 870.00 1816.73FOKUS 1910.00 x 8725.30 910.00 1825.09
RUS 1910.00 8895.45 x 830.00 1835.18GRNET 1910.00 853.41* 1909.02 x 1839.94CINECA 1751.46 1944.39 1844.84 910.00 x
FROM
IP Premium
Loss[%] SWITCH FOKUS RUS GRNET CINECASWITCH x 0.00 0.00 0.02 0.00FOKUS 0.00 x 0.00 0.01 0.00
RUS 0.00 0.00 x 0.02 0.00GRNET 0.00 0.00 0.00 x 0.00CINECA 0.00 3.07 2.70 0.25 x
FROM
IP Premium
MIN AVG MAX MIN AVG MAX MIN AVG MAX MIN AVG MAX MIN AVG MAXSWITCH 37.00 37.00 41.00 50.68 51.31 55.43 112.22 114.29 124.14 17.04 19.91 19.97FOKUS 30.0 38.00 60.00 14.66 17.30 414.66 109.67 110.49 167.59 17.80 20.50 40.00
RUS 50.0 50.00 61.00 10.00 13.00 480.00 186.94 229.82 313.69 29.95 39.62 49.96GRNET 110.0 114.00 190.00 117.00 119.00 141.00 186.90 230.20 254.80 119.80 120.04 127.82CINECA 25.1 27.67 48.41 27.00 30.00 82.00 39.93 42.01 81.85 119.82 120.05 127.82
FROMCINECA
RTT[ms]SWITCH FOKUS RUS GRNET
Nicolas Simar – DANTE - Sequin: Premium IP
Test results IIIJitter 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]
Nicolas Simar – DANTE - Sequin: Premium IP
Testing with IST projects
• AQUILA (IST 1999-10077)– Enhanced architecture for QoS in
Internet– PL (Warsaw) - AT (Vienna), 2.5 Mb/s– activated on 15 April 2002
• MOICANE (IST 2000-26137)– QoS support in access technologies– IT, GR, PT, RO– target time April/May 2002
Nicolas Simar – DANTE - Sequin: Premium IP
Monitoring
Inter-domainmeasurements
Inter-domainmeasurements
backbonenetwork
Customer B
backbonenetwork
Customer A PoP a PoP bPoP n2PoP n1
Customer-to-customer Measurements
Inter-domainmeasurements
End-to-end intra-domainmeasurements Customer BCustomer A
PoP a PoP bPoP n2PoP n1
Inter-domainmeasurements
connection path
Customer BCustomer A
PoP a PoP bPoP n2PoP n1
Intra-domainmeasurements
Intra-domainmeasurements
PoP n3
end-userA
end-userB
end-to-end connection path
PoP am PoP bm
connection path
(a)
(b)
(c)
Nicolas Simar – DANTE - Sequin: Premium IP
Conclusions
• SEQUIN has shown HOW to deploy Premium IP
• NRENs are invited to implement it as a replacement of ATM-based MBS
• The service provisioning model and debugging procedures need to be further elaborated
• Support sought for development of monitoring tools, which is fundamental for the provisioning of the service
Recommended