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Evolution Network. SEAMLESS NETWORK EVOLUTION AT COLT. APRICOT 2018 Kathmandu, Nepal. Amit Dhamija. Amit Dhamija Network Engineering amit.dhamija@colt.net | @AmitDhamijain. Agenda. Colt’s Legacy Network Colt’s VISION for O ne global converged packet network
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Evolution Network SEAMLESS NETWORK EVOLUTION AT COLT APRICOT 2018 Kathmandu, Nepal Amit Dhamija • Amit Dhamija • Network Engineering • amit.dhamija@colt.net | @AmitDhamijain
Agenda • Colt’s Legacy Network • Colt’s VISION for One global converged packet network • Network design evolution towards NextGen technologies • Experiences and Key Takeaways
COLT’S LEGACY NETWORK IGP - ISIS MPLS-LDP BGP – AS 8220 IGP- OSPF MPLS – RSVP/TE T-LDP – PW Ethernet Network IP Network • Services: • Internet access • MPLS L3 VPN’s (unicast and multicast) • Services: • E P2P • Etree • ELAN
Colt’s VISION: One global converged packet network The integration of the network from the service, technology, system and process point of view to offer innovative services, reduce provisioning time, automate end-to-end orchestration and offer truly combined network services. Converged Network Service flexibility Simplified Design & Architecture Resiliency Scalability virtualisation
New Network At a Glance E2E Converged Network (Ethernet / IP / Multicast Services) Infrastructure Protocols Services • EVPN – P2P/E-LAN • IP Services – L3VPN/Internet access • M-VPN – NG multicast VPN’s • ISIS – IGP • MPLS-SR • RSVP • BFD etc.
Legacy Network – MPLS Design MPLS-LDP IP Network MPLS-RSVP Ethernet Network PE-X PE-Y PE-X PE-Y • MPLS-LDP is used as the control plane protocol for IP Network. • MPLS applications – L3 VPN’s/6PE/6VPE. • Shortest IGP Path cost. • Fast convergence. • ECMP Paths. • MPLS-RSVP is used as control plane protocol for Ethernet Network. • MPLS application – VPWS/VPLS • Traffic engineering with explicit paths. • Disjoint paths. • Fast convergence.
Challenges with existing MPLS Design MPLS LDP MPLS RSVP • RSVP traffic engineering LSP’s scalability issues. • RSVP traffic engineering ECMP issues. • LDP-FRR coverage issue. • LDP generates lots of needless labels and is inefficient.
New Network – MPLS Design (Segment Routing) https://datatracker.ietf.org/doc/draft-ietf-spring-segment-routing/ • Why We Chose Segment Routing • Simplicity – Single MPLS design as standard. • MPLS SR supports both modes under one network – (SR-SPT and SR-TE). • Solves the ECMP for traffic engineering by using (Node SID & Adj-SID) algorithm. • Simplifies the control plane for COLT’s new network – solves the RSVP scaling issues/no dedicated MPLS protocols. • Convergence – 100% protection with any topology. • Interoperability with existing MPLS Protocols. • Supports all the existing services. • .
Segment Routing Control Plane PE-N COLT MPLS Segment Routed Network PE-W PE-E PE-S • Deployed using IPv4 transport with MPLS data plane. • Label Allocation – Only loopbacks with Index ID. • SRGB – 100K. • Range – 65K label space per node. router isis COLT net 49.0001.1120.6409.4142.00 interface Loopback0 passive circuit-type level-2-only address-family ipv4 unicast prefix-sid index 4142 explicit-null
Segment Routing – TI LFA Coverage Prefixes reachable in L2 Critical High Medium Low Total Priority Priority Priority Priority All paths protected 0 0 735 1295 2030 Some paths protected 0 0 0 0 0 Unprotected 0 0 0 0 0 Protection coverage 0.00% 0.00% 100.00% 100.00% 100.00%
Segment Routing Integration with IP/LDP Network AdvertiseSR labels for legacy LDP PE Nodes Mapping Servers LDP PE-N Mapping Servers Mapping Servers PE ISIS / MPLS-LDP ISIS / MPLS-SR PE-E PE-W Mapping Servers IP Network PE-S New-Network • Mapping Severs – In path for our deployment. • Features working with this deployment: L3 VPN’s/Internet access/Unicast-v4/v6/QOS etc. • Our use case for Integration: LDP over SR / LDP-SR & SR-LDP.
Segment Routing Traffic Engineering – SR-TE • https://tools.ietf.org/html/draft-filsfils-spring-segment-routing-policy-04 Centralized statefull PCE PCEP SR-TED PCE LSPDB Synch BGP-LS for topology info PCEP for tunnel req & label imposition TED Synch PE-1 PE-2 MPLS SR NSO LSP Setup/ Tear down(On-Demand) • Ongoing evaluation in our engineering lab. • SR-TE features - Disjoint paths with Node/Link and SRLG with static and dynamic paths.
PE-Z Legacy Network – Services Design VRR IRR T-LDP PE-Y PE-Y PE-X BGP/MP-BGP IP Network L2-PE L2-PE G.8032/ERP G.8032/ERP PE-X L2-PE L2-PE • BGP is used as the control plane protocol for IP-Services. • Internet access – IPv4/IPv6(6PE) • Layer 3 VPN’s – VPNv4 and VPNv6(6VPE) • Deployed using RR’s. • ERP in the access rings and T-LDP sessions in the core ring for Ethernet Services. • E-P2P – MPLS-VPWS (Psuedowires) • ELAN – MPLS-VPLS (Mesh of Pseudowires) • E-TREE (Psuedowires based)
Challenges with existing Service Design • Different implementation methods – Layer 3 & Layer 2 VPN’s. • Complicated provisioning and troubleshooting. • Layer 2 VPN’s control and data plane are mixed/flooding issues. • Full mesh of pesudowires required in core network/scalability issues. • Multihomed customers no support of active-active redundancy.
New Network – Services Design (BGP) • Why We Chose EVPN Technology IRR PR’s • Simplicity - Single BGP protocol as the standard for all the services in network. • IP and MAC distribution by using “BGP”. • No use of pseudowires for L2 VPN’s. • Faster convergence for all BGP based services. • Ease of configuration, operations and manageability. BGP Control Plane ERR PE-2 PE-3 ERR BGP- Control Plane BGP- Control Plane AR-1 AR-1 AR-2 AR-2
Ethernet Services (EVPN) P2P Services – MP-BGP https://tools.ietf.org/html/rfc8214 Single BGP Ethernet AD Route containing [RD, RT, ESI, Label(X),Eth-Tag ID(AC)] EVPN NLRI AFI=25/SAFI=70 AR-2 COLT EVPN VPWS Show bgp l2vpn evpn Route Distinguisher: 1111:1111 (default for vrf VPWS:1111) *>i[1][0000.0000.0000.0000.0000][111]/120 10.91.126.111 100 0 I *> [1][0000.0000.0000.0000.0000][222]/120 0.0.0.0 0 i AR-1 • Next Gen solution for Ethernet VPN’s. • EVPN VPWS – Data plane uses MPLS-SR & Control plane – BGP based. • Simple to deploy and scalable solution.
Ethernet Services (EVPN) E-LAN Services – MP-BGP https://tools.ietf.org/html/rfc7432 Four Routes - ELAN Ethernet AD Ethernet MAC ESI Route Inclusive multicast route EVPN NLRI AFI=25/SAFI=70 AR-3 COLT EVPN MPLS Show bgp l2vpn evpn Route Distinguisher: 10.91.126.115:1 *>i[1][10.91.126.115:1][0000.0100.acce.5500.1401][4294967295]/184 10.91.126.115 100 0 i *>i[1][000a.5b7e.7300.0000.0000][0]/120 10.91.126.115 100 0 i *>i[3][0][32][10.91.126.115]/80 10.91.126.115 100 0 I *>i[2][0][48][0000.0200.0001][0]/104 10.91.126.115 100 0 i AR-2 AR-1 • EVPN-MPLS is similar to L3VPN MPLS. • Known Unicast – MPLS-SR as transport & BUM – Ingress Replication with MPLS-SR. • Rapid convergence – non zero ESI for single homed customers.
IP Services using PW-HE Feature – MP-BGP PW-HE binds the L2 EVPN VPWS to the GRT or L3-VPN’s PR’s MP-BGP L3-VPN/GRT PW-HE - VRF PE-2 PE-3 EVPN VPWS EVPN VPWS EVPN VPWS MP-BGP EVPN VPWS MP-BGP AR-1 AR-2 xconnect group xxxxx p2p xxxxx interface PW-Ether1 neighbor evpn evi 787 target 200 source 100 • PW-HE using MPLS-SR as transport – Unicast • PW-HE using MPLS-RSVP as transport - Multicast Logical Interface(PW-HE)
Colt’s Focus towards Network Function Virtualization • Virtualization various network infrastructure segments • RR / PCE Controller/ DDOS controllers etc. • We deploy on commodity x86 hardware & dedicated VM’s for each network function. • We run each instance as an independent island. • Using KVM Hypervisor for our deployment. VNF VNF VNF KVM-Hypervisor x86 HW
Example - Route Reflector Virtualization (vRR) • Next Gen “BGP-RR” deployed for all the services by virtualization of control plane function. • Virtualized all the RR’s on KVM Hypervisor. • Dedicated VM’s for each RR per Server. • Centralized architecture design, each PE forms sessions with all three RR’s. Server 1 Server 2 Server 3 IRR-2 IRR-3 IRR-1 Internet RR VPN-RR-1 VPN-RR-2 VPN-RR-3 MPLS Layer 3 VPN’s RR E-RR-1 E-RR-2 E-RR-3 Ethernet RR
Operations: Experiences from our Deployment • All MPLS Services are fully supported by Segment Routing. • L2 VPN’s / VPLS / EVPN / L3 VPN’s / IPv6. • LDP-SR Inter working full multi-vendor support (Cisco/Juniper & Nokia, in our case). • ISIS doesn’t advertise the merge flags when destination prefix looses the last backup path – Patch! • Inconsistency in forwarding entries in LC and RP due to TI-LFA bug – Patch! • No labels assignment for connected prefixes other then loopbacks on MPLS-SR ( SR feature Limitation). • Native multicast solution for SR not yet available (Tree-SID, BIER etc.) • Max SID Depth is a problem with SR-TE due to nature of source routing – Binding SID! • No Interop issue in EVPN between Cisco/Juniper & Nokia. • EVPN Flow based load balancing no support at this stage. • Hierarchical EVPN for large networks is still a challenge.
Key Takeaways • Single Infrastructure for all services.. • Simplified the transport and service architecture. • Reduce the cost – opex and capex. • Faster Service delivery. • Better Orchestrator. • It’s good to be an early investor in any new technology. • Benefits Realized with Next Gen MPLS technologies – simplified design, deployment & operations. • Next Gen MPLS technologies proved easy to deploy, maintain and use. • Questions?
Thank you For your time amit.dhamija@colt.net