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New Member

RFC 4363 question

My understanding of RFC 4363(10a) is that it is intended to be used to provide reach from one MPLS  network into another MPLS network in another AS for the purpose of  providing carrier transparent support for MPLS VPN customers that have a  physical presence in both networks.

However, could RFC 4363(10a) be used between two carrier networks where one is an MPLS network and  the other is a native IP only network?  The desire being for the native  IP network to be able to provide IP services such as VoIP to customers built on the MPLS network.  If so, can someone point me to documentation and example configurations for this type of setup on the non-MPLS side?   I have been looking at section 4 of "Implementing Advanced Features on MPLS-Based VPNs", which if I'm reading correctly applies in this type of situation.


Cisco Employee

Re: RFC 4363 question


I am not sure if I understand you correctly. If interconnecting two ISPs and one of them is a normal pure-IPv4 ISP while the other is an MPLS VPN ISP then from the viewpoint of the MPLS VPN provider, the IPv4 ISP is simply a customer. It probably does not make much sense to create a VRF on the IPv4 ISP's PE router if there is no MPLS in his network.

Could you perhaps explain your idea and/or needs in more detail - an example perhaps?

Best regards,


New Member

Re: RFC 4363 question

>>from the viewpoint of the MPLS VPN provider, the IPv4 ISP is simply a customer.

I agree, and the solution I've discussed is a straight layer 3 connection between the two networks.  This would allow application traffic (hosted by the IPv4 network) to be exchanged with customers on the MPLS network without traversing the internet, giving a greater ability to control the quality of the service.   However, discussions about cpe visibility and questions relating to QoS on the public portion of the MPLS provider's network have driven the discussion in this direction.

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