Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20051

Overview of RSVP-TE Network Simulator:

Design and Implementation

D.Adami, C.Callegari, S.Giordano,

F.Mustacchio, M.Pagano, F.Vitucci

Dipartimento di Ingegneria dell’Informazione:

Elettronica, Informatica, Telecomunicazioni

Università di Pisa

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20052

Outline

• Motivations and Requirements• a MPLS Node Simulator (MNS) based on the Constrained Routing –

Label Distribution Protocol (CR-LDP) is available in NS2 but…..

• MPLS node implementation• strict distinction between control and data plane

• RSVP-TE\ns module• RSVP-TE enhancements for LSP handling

• simulator functions

• Functional validation test

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20053

Motivations

• A MPLS Network Simulator (MNS) is available in the Network Simulator 2 (NS2)

• developed at Chungnam National University, Korea• based on the Constrained Routing – Label Distribution Protocol (CR-LDP)

• But …– IETF RFC 3468 states:

• “Multiprotocol Label Switching (MPLS) Working Group within the IETF focus its efforts on “Resource Reservation Protocol (RSVP)-TE: Extensions to RSVP for Label-Switched Paths (LSP) Tunnels” (RFC 3209) as the MPLS signalling protocol for traffic engineering applications and undertake no new efforts relating to “Constraint-Based LSP Setup using Label Distribution Protocol (LDP)” (RFC 3212)”.

– CCAMP Working Group survey• A survey of GMPLS implementations was published in June 2002. It

includes responses from 22 different implementers. Twenty-one of 22 implementations include the GMPLS signalling based on RSVP-TE while only 3 include signalling based on CR-LDP.

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20054

Motivations

• RSVP-TE Network Simulator will be useful to assess the feasibility of innovative mechanisms in different network scenarios:

– MPLS networks (MPLS Working Group)• Encoding of Attributes for Multiprotocol Label Switching (MPLS) Label

Switched Path (LSP) Establishment Using RSVP-TE• Extensions to RSVP-TE for Point to Multipoint TE LSPs

– DiffServ-aware MPLS networks (MPLS Working Group)• RFC 3568 defines the concept of Classtype but no RSVP-TE enhancements

have been standardized yet to support such an information

– GMPLS networks (CCAMP Working Group)• RSVP-TE Extensions in support of End-to-End Generalized Multi-Protocol

Label Switching (GMPLS)-based Recovery

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20055

Requirements

• Overall design requirements

– Standard compliance: with respect to IETF Standardization documents (e.g RSVP-TE RFC 3209)

– Extensibility: enhancements in the signalling protocol and in the control plane mechanisms should be easily introduced in the simulator

– Modularity: it should be possible to combine different modules implementing distinct functionalities (e.g. use of different scheduling algorithms)

– Open source code: Network Simulator version 2

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20056

MPLS node implementation

• To develop a full comprehensive simulation environment for MPLS networks the following functionalities are required:

– Data plane mechanisms (label swapping, traffic mapping, etc.)

– Control plane mechanisms (MPLS signalling protocol: RSVP-TE o CR-LDP)

Source

Destination

Label Switched Path (LSP) 1

Label Switched Path (LSP) 2

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20057

MPLS node implementation in the NS2 simulator

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20058

MPLS node implementation: control plane

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 20059

MPLS node implementation: data plane

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200510

RSVP-TE\ns module

• RSVP-TE object added or modified in the PATH message:• SESSION• LABEL_REQUEST• SENDER_TEMPLATE• SENDER_TSPEC• EXPLICIT ROUTE OBJECT (ERO)• RECORD ROUTE OBJECT (RRO)• SESSION_ATTRIBUTE

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200511

RSVP-TE\ns module

• RSVP-TE object added or modified in the PATH message:• SESSION• LABEL_REQUEST• SENDER_TEMPLATE• SENDER_TSPEC• EXPLICIT ROUTE OBJECT (ERO)• RECORD ROUTE OBJECT (RRO)• SESSION_ATTRIBUTE

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200512

RSVP-TE\ns module

• RSVP-TE object added or modified in the RESV message:• SESSION

• FLOW_SPEC

• FILTER_SPEC

• STYLE

• LABEL

• RECORD ROUTE OBJECT (RRO)

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200513

Simulator functions

• LSP establishment– Commands:<Ingress-LER> create-erlsp-rsvpte <Egress-LER> <sessionID> <FlowID> <TunnelID> <er><Ingress-LER> create-erbwlsp-rsvpte <Egress-LER> <sessionID> <FlowID> <TunnelID> <rate> <bucket> <ttl> <er>

– Action:• a PATH message is sent by the Ingress Label Edge Router (LER)

towards the Egress LER– An explicit route could be specified by means of the ERO Object

• After the Egress LER receives the PATH message, a RESV message is sent upstream

• The RESV message is processed by each Label Switched Router (LSR) along the path, which, in turn, performs label allocation and optionally resource reservation

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200514

Simulator functions

• Mapping traffic flows to a LSP:– Command:<Ingress-LER> bind-flow-LSP <Dest Address> <FlowID> <TunnelID>

– Action:• Traffic flow is mapped onto the LSP

• LSP release:– Command:<Ingress-LER> release-LSP <SessionID> <FlowID>

– Action:• a PATH_ERR message is sent by the Ingress Label Edge Router

(LER) towards the Egress LER• labels and resources are released along the PATH

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200515

Simulator functions

• Failure handling– Command:<Upstream node> break-link <Downstream node>

– Action:• a PATH_ERR message is sent by the LSR (Upstream node)

towards the Ingress LER for each LSP

• In turn, the Ingress LER sends a PATH_TEAR message to release resources

• a RESV_ERR message is sent by the LSR (Upstream node) towards the Egress LER for each LSP

• In turn, the Egress LER sends the corresponding RESV_TEAR message to release resources

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200516

Functional validation test

• Objective– to assess LSP establishment, flow mapping and failure

handling in the RSVP-TE Network Simulator

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200517

Functional validation test

• Objective– to assess LSP establishment, resource allocation, traffic

engineering mechanisms and flow mapping in the RSVP-TE Network Simulator

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200518

Functional validation test (NAM animation)

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200519

Conclusions

• A full comprehensive MPLS network simulation environment based on the RSVP-TE signalling protocol has been developed

• Thank to its modularity and extensibility this simulation environment could be useful to speed-up the design, development and deployment of enhanced (G)MPLS networks

• The software is available on the TlcNetGroup software repository at the site: wwwtlc.iet.unipi.it

Fabio Mustacchio - IPS-MOME 2005 – Warsaw, March 15th 200520

Questions?

Thank you