MPLS: connection CE to PE via third not-mpls ISP

Unanswered Question
Nov 7th, 2007
User Badges:
  • Bronze, 100 points or more


I have a couple of simple questions regarding MPLS and would be appreciate to every help:

question is:

Is it stricly necessary that CE and PE (in MPLS terms) routers are directly connected? Or is it possible to create CE-PE interconnection via Internet connection?

what I mean is, let say we have an ISP provider for datacenter network (our responcibilty) and second ISP provider for office (office's ISP responcibility). ISP provider for office will sell us MPLS services and will interconnect all our offices (may be a good idea). The question is how we should connect our datacenter network to the office MPLS network? should office ISP install new physical link to our datacenter network or we can use public ip addresses to establish a CE-PE connection?

I hope the picture helps to understand:

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4 (2 ratings)
arun kumar Wed, 11/07/2007 - 03:42
User Badges:
  • Bronze, 100 points or more

In MPLS-VPN scenario, CE router should terminate on a PE which is enabled with MPLS. If you have disparate network and want to extend the MPLS services over non-MPLS network, then you can extend your CE logically till your PE (MPLS enabled) by

1) Configuring L2TPv3 - Pseudowire between your CE and PE over IP network

2) if the non-MPLS network is via Metro then it can be done with QinQ configuration.


shivlu jain Wed, 11/07/2007 - 05:30
User Badges:
  • Silver, 250 points or more

If you want to conenct your data center thn it should be connected to your MPLS cloud.

After that you can create a internet vrf in your internet router and impose a static route to the outside world.

In this way your vpnv4 and vrf customers both will work .

If your CPE is not directly connect and you are not running MPLS at tier 3 pop thn you can user pseudowire. If you req confiuration for that ask me i will send you all the details.





arun kumar Sun, 11/11/2007 - 20:43
User Badges:
  • Bronze, 100 points or more


One of the easiest way in this scenario would be creating a GRE tunnel from CPE to PE.. and in PE apply the VRF on the "GRE int Tunnel". But you might face problems related to MTU issues in this scenario...

Konstantin Dunaev Mon, 11/12/2007 - 06:46
User Badges:
  • Bronze, 100 points or more

thank you, for answers!

we've considered MPLS only because we wanted to get rid of GRE tunels :).

but if need the use GRE tunnel to connect our router cloud then there is no much sence for us to use the MPLS at all :)


This Discussion