Transcript Service 1

Pseudowire Edge to Edge
Emulation
FROM THE SERVICE PROVIDER POINT OF VIEW
[email protected]
Drivers For PWE3/L2TPv3 (1)

Adding to the product portfolio a service
that emulates “circuit-like” connections
over a single or multiple (inter-AS) IP
networks for Point-To-Point circuits or
Point-To-Multipoint circuits
 Having a performing and flexible toolbox
for building customized solutions in the
case of conflicting routing policies
requirements:
open versus closed peering networks
regional/national vs. hosting vs.
international transit backbone
policies
Drivers For PWE3/L2TPv3 (2)

Interconnecting at high-speed physically
disjoint network parts by building a
“network based overlay” architecture.

Provide a mean for interconnecting
Ethernet networks transparently.
Service Provider Requirements

Transparency
No change to the routing architecture
No new IP protocol implementation
 Run over “plain” IP
 High-speed capable
from T1/E1/E3/T3 to OC48
 High performance
Hardware assisted (server card) for
high BW
 Flexible
In terms of payload capability:
Layer 2: PPP ,HDLC ,FR ,ATM ,ETHERNET
Service Provider Requirements

Easy and quick service provisioning
 Secure
Solution: Simple Security with Tunnel
ID/Key vs. IPSec capable
 Scalable
need for automatically/auto-magically
tunnels setup
 Minimum overhead
Tunnel Header: 4-12 bytes
 Takes benefit of the statistical
multiplexing of the IP networks
Services Overview – IP VLL
 Service 1: IP Virtual Leased Line
(1)
 Emulation
of HDLC, PPP, FR, ATM,
Ethernet End-to-End interconnectivity
Transport of Layer 2 packets End-toEnd
 Point-To-Point
Single
Virtual Leased Line/physical
interface
One-to-One mapping: 1 tunnel bound
to the interface
Services Overview – IP VLL
(2)
Services Overview – IP VLL
(3)  Examples:
 Lan
To Lan (L2L) interconnection aka.
Transparent Lan Service (TLS)
 Replacement of clear channel SDH
Finer granularity in bandwidth
(combined with existing IP rate-limiting
tools)
 Interconnection of 2 disjoint networks
at high-speed
 Layer 2 backhaul to a remote location
Virtual presence at IX (no need for
expensive LL)
Services overview–IP MVLL (1)
 Point-To-Multipoint

Multiple Virtual Leased
Lines/physical interface
Multiple tunnels with
DLCI/802.1Q/[VPI/VCI] mapping to the
corresponding sub-interface on the
single physical interconnection
Services overview–IP MVLL (2)
Services overview–IP MVLL (3)
 L2
PPVPN (Provider Provisioned Virtual
Private Network).
Different topologies:
Hub-and-Spoke,Partial/Fully Mesh
Single Interconnection/site
Customer manage Routing and QoS
Tunnels provisioned by the Provider:
“Network based tunneling”
Services overview–IP MVLL (4)
Services overview–IP MVLL (5)
 Overlay
network
Goal: The network D in the middle does
not need to know about the routing in the
other disjoint networks and has a different
BGP/routing policy (more restricted for
instance)
To scale one transit backbone
Superset and subset of routes
Open versus closed peering policy
Closed User Group (GRX )
Distributed IX
Services overview–IP MVLL (6)
Services overview–IP MVLL (7)
 Premium
Service
Goal: bundle different services on a single
interface.
Examples:
a) Transit connectivity + multiple direct
connectivity to regional peering
b) L2PPVPN + Internet Break-out +
Managed Hosting/Housing Services
Services overview–IP MVLL (8)
Other Services (1)

Metro TLS (Transparent LAN Services)
Interconnection of LANs in the Metro Area
Break-out to remote MANs, Internet, CUG
(intranet/extranet), etc.
Other Services (2)
Other Services (3)

Multi-services devices:
On same the router, connect:
 L2 PPVPN customers
 L2 Backhaul service
 IP transit
 Inter-Connectivity to different networks
(regional/national) with different routing
policies
 Premium service with different QoS
requirements
 VLAN rewriting/stripping
VLAN rewriting/stripping
Future (1)

Control plane for the forwarding plane
 Enhanced security
 Automatically tunnel setup
 L2/L3 (dissimilar endpoints framing)
 L3/L3 (similar to GRE)
Tips:
 MTU at endpoint interconnections <
Maximum core MTU – (20 bytes for IP
Header) – 4 to 12 bytes for Tunnel Header
(in today’s implementation -> no support
for fragmentation)
 ISIS hello padding  disable it or set
correct MTU at the edge
Conclusion
PWE3/L2TPv3 is a high performance
transparent encapsulation protocol
optimized for the encapsulation of one
protocol (L2&L3)over IP. No change to the
network is required (runs over IPv4).