Mpls Interoperability; Mtu And Retry Limit - Avaya 8800 Planning And Engineering, Network Design

MPLS IP VPN and IP VPN Lite
A CE device exchanges routing information with a PE device using EBGP. The routing engine in the
CE device works with EBGP running in the context of a VRF in the PE device. This suits carrier
deployments.
When the Ethernet Routing Switch 8800/8600 is used as a PE device, the following are the means
by which a PE device can connect to a provider core device:
• One PE connect to a single provider core router using a single GbE, 10 GbE, or 10/100/1000
Mbit/s port.
• One PE multilink trunks to a single provider core using multiple (up to eight) GbE, 10 GbE, or
10/100/1000 Mbit/s ports.
• One PE connects to two Ps (without SMLT support).
• PE directly connects to PE.
A PE device exchanges routing information with a provider core device using an IGP and static
routes. The global routing engine in the PE device works with the routing protocol running in the
context of a global routing engine in the provider core device.
For detailed IP VPN configuration examples, see IP-VPN (MPLS) for ERS 8800/86000 Technical
Configuration Guide, NN48500-569 and IP-VPN and IP-LER Interoperability for Ethernet Routing
Switch Technical Configuration Guide, NN48500-571. For detailed VRF Lite configuration examples,
see VRF-Lite for Ethernet Routing Switch 8800/8600 Technical Configuration Guide, NN48500-570.

MPLS interoperability

The Avaya Ethernet Routing Switch 8800/8600 MPLS implementation has been verified with:
• Cisco 7500 (with RSVP, Cisco cannot function as the RSVP egress LER when used with the
Ethernet Routing Switch 8800/8600)
• Juniper M10

MTU and Retry Limit

The MPLS maximum transmission unit (MTU) is dynamically provisioned (1522 or 1950 bytes) and it
supports jumbo frames (9000 bytes). Packets that exceed the MTU are dropped. The allowed data
CE frame size is MTU size minus MPLS encapsulation (header) size. For control frames (for
example, LDP) the frame size is 1522 or 1950 bytes.
For the Avaya Ethernet Routing Switch 8800/8600, the MPLS RSVP LSP Retry Limit is infinite by
design (a setting of zero means infinite). When the limit is infinite, should a Label Switched Path
(LSP) go down, it is retried using exponential backoff. The Retry Limit is not configurable.
June 2016 Planning and Engineering — Network Design
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