CEoP and MPLS

Abid Abdul Latif · ‎04-25-2011

Hi,

I have a basic question is what is the difference between Mpls layer 2 VPN and CEoP ? Why do i have to go for specific CEoP based modules. When i can do xconnect using other E1 modules too ?

Any clarification would be appreciated.

Regards

Luc De Ghein · ‎04-25-2011

Hi,

MPLS L2VPN and CEoP use the same packet switched network infrastructure and use the same

pseudowire signalling. However, CEoP demands special structure, as we deal with TDM/Circuit Emulation.

2 important RFCs:

RFC 5085:

   A method for encapsulating structured (NxDS0)
   Time Division Multiplexed (TDM) signals as pseudowires over packet-
   switching networks (PSN)

and

RFC 4553:

This document describes a pseudowire encapsulation for Time Division

   Multiplexing (TDM) bit-streams (T1, E1, T3, E3) that disregards any
   structure that may be imposed on these streams, in particular the
   structure imposed by the standard TDM framing.

Because this is TDM, the clocking is important, hence the special HW requirements.

Thanks,

Luc