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

I GP route MPLS tunnel

! !

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

Service Provider Network

! !

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 Based Solutions MPLS Based Solutions

Path Redundancy Path Redundancy

Primary LSP Backup LSP Physical link

! !

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) Service Provider Network

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

Primary LSP Detour LSP Physical link 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 Service Provider Network

MPLS Based Solutions MPLS Based Solutions

Load Balancing Load Balancing

Equal cost LSP Equal cost LSP Physical link

! !

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 Service Provider Network

MPLS Based Solutions MPLS Based Solutions

Link Bundling Link Bundling

Transit backbone Transit backbone Metro Network San Francisco Metro Network New York

! !

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 Mapping IP ToS to LSPs LSPs

Gold LSP Bronze LSP Physical link

! !

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 Service Provider Network

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 Mapping IP ToS ToS to to Exp Exp

! ! 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

TTL Label (20 bits) Exp S

32-bits

MPLS Header

MPLS Based Solutions MPLS Based Solutions

Quality of Service Quality of Service

10 Mbit/ s LSP 20 Mbit/ s LSP Physical link

! !

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) Service Provider Network

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

Metro VPN Services Metro VPN Services

MPLS Virtual Leased Line MPLS Virtual Leased Line

Customer Site in San Francisco Customer Site in New York

! !

MPLS VLL Service MPLS VLL Service – – pair of LSP’s of opposite directions forming a single virtual pipe pair of LSP’s of opposite directions forming a single virtual pipe – – Size of pipe based on traffic characteristics Size of pipe based on traffic characteristics

• Can be dynamically changed

Can be dynamically changed – – Explicitly routed L2 tunnel for guaranteed service Explicitly routed L2 tunnel for guaranteed service

! !

Offers a self-healing point to point connection Offers a self-healing point to point connection

! !

Requires MPLS L2 tunneling support Requires MPLS L2 tunneling support – – Ethernet in IP/GRE in MPLS Ethernet in IP/GRE in MPLS – – Martini draft Martini draft

! !

Requires per LSP rate limiting/shaping Requires per LSP rate limiting/shaping L2 Tunnel

Metro VPN Services Metro VPN Services

MPLS Transparent LAN Service MPLS Transparent LAN Service

Inter-Exchange Carrier providing inter-city connectivity

Tunnel LSP VLAN LSP 802.1Q

POP Last Mile POP Last Mile POP Last Mile

! !

.1Q tagged traffic tunneled in LSP’s .1Q tagged traffic tunneled in LSP’s – – LSP’s appear as .1Q trunk LSP’s LSP’s appear as .1Q trunk LSP’s

! !

.1p mapped into Exp bits or into different QoS LSP’s .1p mapped into Exp bits or into different QoS LSP’s

Metro VPN Services Metro VPN Services

MPLS TLS: ZOOM in POP MPLS TLS: ZOOM in POP

Port 3 - Customer X Port 5 - Customer Y VLAN Blue VLAN Blue LSP 300 LSP 500 Port 8 AR CR LSP 1000 POP

! !

Label hierarchy Label hierarchy – – Customers’ VLAN ‘s are mapped to specific “VLAN LSP’s” in order Customers’ VLAN ‘s are mapped to specific “VLAN LSP’s” in order to allow private VLAN Id spaces to allow private VLAN Id spaces – – “VLAN LSP’s” are tunneled in the core within a “Tunnel LSP” used “VLAN LSP’s” are tunneled in the core within a “Tunnel LSP” used to carry traffic between POP’s to carry traffic between POP’s

! !

L2 policy example L2 policy example

– – Traffic from Port 3 & VLAN Blue to be sent to Port 8 & LSP 300 Traffic from Port 3 & VLAN Blue to be sent to Port 8 & LSP 300

Metro VPN Services Metro VPN Services

VLL/TLS Models VLL/TLS Models

! ! Martini tunnels

Martini tunnels

– – Carry ATM/Frame Relay/Ethernet Carry ATM/Frame Relay/Ethernet – – Sequencing capability Sequencing capability – – No fragmentation support No fragmentation support

• Requires jumbo frame support

Requires jumbo frame support

! ! IP/GRE over MPLS tunnels

IP/GRE over MPLS tunnels

– – Bridged IP traffic Bridged IP traffic

• Can be pre-fragmented

Can be pre-fragmented

– – if transit network can not carry large if transit network can not carry large frames frames – – if no IP MTU path discovery support if no IP MTU path discovery support

Metro VPN Services Metro VPN Services

Two MPLS VPRN models Two MPLS VPRN models

! ! Virtual Router

Virtual Router

– – per VPN routing protocol instance per VPN routing protocol instance – – per VPN RIB and FIB per VPN RIB and FIB – – No protocol extensions No protocol extensions

! ! BGP VPN

BGP VPN

– – MP-BGP exchanges extended VPN-IP MP-BGP exchanges extended VPN-IP addresses between PE routers addresses between PE routers

• PE translates these CE advertized IP

PE translates these CE advertized IP addresses into unique VPN-IP addresses into unique VPN-IP addresses addresses

• VPN-IP addresses exchanged via

VPN-IP addresses exchanged via MP-BGP only to PE routers member MP-BGP only to PE routers member

• f corresponding VPN
• f corresponding VPN

MPLS IP MPLS IP VPNs VPNs: On a collision course : On a collision course

! ! VR and BGP VPN offer similar services

VR and BGP VPN offer similar services

– – PE/VR and CE routers attached to a PE/VR and CE routers attached to a specific VPN exchange which addresses specific VPN exchange which addresses are reachable via are reachable via

• Static routing

Static routing

• RIP/OSPF/BGP

RIP/OSPF/BGP – – MPLS tunnel between PE/VR routers MPLS tunnel between PE/VR routers

• Core routers are VPN unaware

Core routers are VPN unaware

Conclusion Conclusion

Best of Two Worlds Best of Two Worlds

! ! MPLS is the evolution of current IP

MPLS is the evolution of current IP and connection oriented protocols and connection oriented protocols

– – Strength and scalability of IP routing Strength and scalability of IP routing – – PVC like connectivity PVC like connectivity – – ATM like QoS ATM like QoS – – Explicit routing Explicit routing

! ! Plus

Plus

– – Path protection/optimization Path protection/optimization – – Load balancing Load balancing

Scalability of MPLS Scalability of MPLS

! ! Smart Routed Edge

Smart Routed Edge

– – Packet classification Packet classification

• Prioritization/Marking

Prioritization/Marking

• FEC to LSP/

FEC to LSP/Exp Exp mapping mapping – – Rate limiting/shaping Rate limiting/shaping – – ACL’s ACL’s

! ! Simple Switched Core

Simple Switched Core

– – Label swapping Label swapping – – Uses extended routing protocols to Uses extended routing protocols to signal LSP’s signal LSP’s

Key MPLS Applications Key MPLS Applications

! ! Differentiated & Guaranteed services

Differentiated & Guaranteed services

! ! Traffic Engineering

Traffic Engineering

! ! VPNs

VPNs

– – Transparent LAN Services Transparent LAN Services – – Virtual Leased Line Services Virtual Leased Line Services – – Routed Routed VPNs VPNs

Thank You Thank You

Acronyms Acronyms

ACL ACL Access Control List Access Control List ATM ATM Asynchronous Transfer Mode Asynchronous Transfer Mode BGP BGP Border Gateway Protocol Border Gateway Protocol CoS CoS Class of Service Class of Service CR-LDP CR-LDP Constraint based Label Distribution Protocol Constraint based Label Distribution Protocol CSPF CSPF Constrained Shortest Path First Constrained Shortest Path First ER-LSP ER-LSP Explicitly Routed LSP Explicitly Routed LSP FEC FEC Forward Equivalency Class Forward Equivalency Class GRE GRE Generic Routing Encapsulation Generic Routing Encapsulation IGP IGP Interior Gateway Protocol Interior Gateway Protocol ISIS ISIS Intermediate System to Intermediate System Intermediate System to Intermediate System LDP LDP Label Distribution Protocol Label Distribution Protocol LSP LSP Label Switched Path Label Switched Path MPLS MPLS Multi-Protocol Label Switching Multi-Protocol Label Switching OSPF OSPF Open Shortest Path First Open Shortest Path First QoS QoS Quality of Service Quality of Service RSVP RSVP Resource Reservation Protocol Resource Reservation Protocol TE TE Traffic Engineering Traffic Engineering TLS TLS Transparent LAN Service Transparent LAN Service ToS ToS Type of Service Type of Service VLL VLL Virtual Leased Line Virtual Leased Line VPN VPN Virtual Private Network Virtual Private Network VPRN VPRN Virtual Private Routed Network Virtual Private Routed Network