Subject: Re: LDP usage in MPLS based VPNs

From: [email-masked]
Date: Thu, 27 Sep 2001 10:58:16 -0500

MPLS allow us to use the standard IP routing protocols such as OSPF or 
ISIS to know the network topology and establish LSP. When establishing 
LSP, either LDP or RSVP can be used. All the routers on the signaling 
path between two peer PE routers (including the P routers) must support 
the LDP or RSVP.

BGP is only between the peer PE routers in a specific VPN because the 
RD and Route Target information are needed to be included in BGP 
advertisement message. The P routers between the peer PE routers 
doesn't have to support BGP. Actually, the BGP advertisement message 
between peer PE routers are transparent to the P routers in between.

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Shujia GONG (Frank)
Advanced Internet Laboratory
George Mason University
MSN 2G9 Johnson Ctr G10
4400 University Drive 
Fairfax, Virginia 22030
Tel: +1(703)9933905
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