MPLS as a Service MPLS as a Service Enabler in Metro Enabler in - PowerPoint PPT Presentation

MPLS as a Service MPLS as a Service Enabler in Metro Enabler in Metro Area Networks? Area Networks? Marc Lasserre Marc Lasserre marc@riverstonenet.com www.riverstonenet.com

Service Provider Challenges Service Provider Challenges The Driving Needs for MPLS The Driving Needs for MPLS ! Provide a high quality service to Provide a high quality service to ! their customers their customers – High availability High availability – – High reliability High reliability – – High performance High performance – ! Offer new services Offer new services ! – Tiered services Tiered services – – Guaranteed services Guaranteed services – – VPN services VPN services – – Transparent LAN services Transparent LAN services – ! Maintain a scalable network Maintain a scalable network !

Service Provider Requirements Service Provider Requirements ! High Availability High Availability ! – Ability to dynamically recover from Ability to dynamically recover from – node or link failures node or link failures • Automatic re-route Automatic re-route • • Path restoral Path restoral • ! High Reliability High Reliability ! – Node/Link Redundancy Node/Link Redundancy – • Path protection Path protection • ! High Performance High Performance ! – Minimize congestion using traffic Minimize congestion using traffic – engineered paths engineered paths – Load balancing Load balancing –

MPLS Based Solutions MPLS Based Solutions Traffic Engineering Traffic Engineering Service Provider Network I GP route MPLS tunnel Current routing protocols follow the shortest path leading to : Current routing protocols follow the shortest path leading to : ! ! – – Over-utilized northern route Over-utilized northern route – – Under-utilized southern route Under-utilized southern route MPLS allows explicitly routed LSP’s to be set up MPLS allows explicitly routed LSP’s to be set up ! ! – e.g. set up path via routers with low latency – e.g. set up path via routers with low latency MPLS policies define how traffic is mapped on different LSP’s MPLS policies define how traffic is mapped on different LSP’s ! ! – – e.g. all RTP traffic follows the green LSP e.g. all RTP traffic follows the green LSP

MPLS Based Solutions MPLS Based Solutions Path Redundancy Path Redundancy Service Provider Network Physical link Primary LSP Backup LSP Redundant LSP's can be setup for traffic protection Redundant LSP's can be setup for traffic protection ! ! Backup LSP can be a hot standby LSP or dynamically signaled Backup LSP can be a hot standby LSP or dynamically signaled ! ! upon failure of the primary LSP upon failure of the primary LSP – – If blue LSP fails, switch traffic to green LSP if available or signal If blue LSP fails, switch traffic to green LSP if available or signal green LSP (ER-LSP preferably) green LSP (ER-LSP preferably)

MPLS Based Solutions MPLS Based Solutions Failure detection Failure detection ! Link Layer indication Link Layer indication ! ! Signaling Signaling ! – RSVP Hello RSVP Hello – • Node is considered down after 20 ms Node is considered down after 20 ms • – Sonet-like protection is possible Sonet-like protection is possible – – LDP Hello/Keepalive LDP Hello/Keepalive –

MPLS Based Solutions MPLS Based Solutions Fast Rerouting Fast Rerouting Service Provider Network Physical link Primary LSP Detour LSP Detour LSP Fast Reroute signaling option to create detour paths Fast Reroute signaling option to create detour paths ! ! – Alternate detour around failure used while ingress LER is – Alternate detour around failure used while ingress LER is notified to re-compute new ER-LSP notified to re-compute new ER-LSP

MPLS Based Solutions MPLS Based Solutions Load Balancing Load Balancing Service Provider Network Physical link Equal cost LSP Equal cost LSP Traffic can be load balanced across multiple equal cost LSP’s Traffic can be load balanced across multiple equal cost LSP’s ! ! – If one of the LSP’s fails, traffic will automatically be sent across – If one of the LSP’s fails, traffic will automatically be sent across the other links the other links • • High priority traffic will go first High priority traffic will go first

MPLS Based Solutions MPLS Based Solutions Link Bundling Link Bundling Transit backbone Metro Network Metro Network San Francisco New York Transit backbone For route diversity, inter-metro connection uses separate providers For route diversity, inter-metro connection uses separate providers ! ! Two diverse paths can be bundled to form a resilient bigger pipe Two diverse paths can be bundled to form a resilient bigger pipe ! ! Additional LSP’s can be added to the pipe as traffic grows Additional LSP’s can be added to the pipe as traffic grows ! !

MPLS Based Solutions MPLS Based Solutions Mapping IP ToS to LSPs LSPs Mapping IP ToS to Service Provider Network Physical link Gold LSP Bronze LSP Multiple differentiated paths can be set up to satisfy some soft Multiple differentiated paths can be set up to satisfy some soft ! ! quality of service requirements quality of service requirements – – High priority traffic such as voice is carried over a gold LSP High priority traffic such as voice is carried over a gold LSP • • Gold LSP is traffic engineered to meet voice latency/jitter Gold LSP is traffic engineered to meet voice latency/jitter requirements requirements – – Best effort traffic such as Internet data traffic is carried over a Best effort traffic such as Internet data traffic is carried over a bronze LSP bronze LSP

MPLS Based Solutions MPLS Based Solutions LSP Preemption LSP Preemption ! If an LSP can not be established If an LSP can not be established ! because of insufficient resources, because of insufficient resources, that LSP can preempt other LSP's of that LSP can preempt other LSP's of lower priority lower priority – Setup priority > Holding priority Setup priority > Holding priority – ! If the gold LSP goes down and there If the gold LSP goes down and there ! are no resources available to set up are no resources available to set up a new one, the gold LSP will a new one, the gold LSP will preempt the bronze LSP preempt the bronze LSP

MPLS Based Solutions MPLS Based Solutions Mapping IP ToS ToS to to Exp Exp Mapping IP Label (20 bits) Exp S TTL 32-bits MPLS Header ! ToS/DSCP/802.1p code points can ToS/DSCP/802.1p code points can ! be mapping to Exp (a.k.a CoS) bits be mapping to Exp (a.k.a CoS) bits – Used to choose priority queue, Used to choose priority queue, – scheduling and drop policies scheduling and drop policies – Hop by hop processing Hop by hop processing –

MPLS Based Solutions MPLS Based Solutions Quality of Service Quality of Service Service Provider Network Physical link 10 Mbit/ s LSP 20 Mbit/ s LSP Signaled LSP's can specify traffic parameters such as Signaled LSP's can specify traffic parameters such as ! ! – – Bandwidth/Priority/Affinity Bandwidth/Priority/Affinity Extended OSPF-TE and ISIS-TE provide real-time feedback on Extended OSPF-TE and ISIS-TE provide real-time feedback on ! ! network resources network resources – – Online and offline CSPF computation Online and offline CSPF computation • Used to set up differentiated LSP’s (e.g. voice,video,data) • Used to set up differentiated LSP’s (e.g. voice,video,data)

MPLS Based Metro VPN Services MPLS Based Metro VPN Services ! Virtual Leased Line (VLL) Virtual Leased Line (VLL) ! – Emulation of a PTP link Emulation of a PTP link – ! Transparent LAN Service (TLS) a.k.a Transparent LAN Service (TLS) a.k.a ! VPLS VPLS – Emulation of a LAN Emulation of a LAN – – Forwarding based on L2 reachability Forwarding based on L2 reachability – information information ! Virtual Private Routed Network Virtual Private Routed Network ! (VPRN) a.k.a IP VPN’s (VPRN) a.k.a IP VPN’s – Emulation of multi-site routed network Emulation of multi-site routed network – – Forwarding based on L3 reachability Forwarding based on L3 reachability – information information

Impediments to Metro VPN Services Impediments to Metro VPN Services ! MPLS standards only specify MPLS standards only specify ! – VLL VLL – – IP VPN’s IP VPN’s – ! TLS support requires additional TLS support requires additional ! extensions extensions – Transparent bridging support Transparent bridging support – • Broadcast support Broadcast support • • Address learning Address learning • • Split-horizon Split-horizon • – L2 FEC’s L2 FEC’s –