Subject: Re: [FW: ce range in l2 mpls vpns ]

From: eduard metz <[email-masked]>
Date: 23 Nov 00 16:53:17 MET

juha, 

i think we agree ...

the mapping you describe (vpi to sub-interface, and thereby creating a
relation between sub-interface and remote-site), is what i mean with
"alignment of pe/ce configuration". since the pe applies specific logic in the
way it connects local ce-pe circuits to remote sites, you have to be aware of
this logic when configuring the vpi to sub-interface mapping.

adding more scenarios for some common cases to the draft could help explain
this.

cheers, eduard

Juha Heinanen <[email-masked]> wrote:
eduard metz writes:

 > however, there
 > are many situations in which this is not the case. for example: when
 > the network is treated as a collection of point-to-point links (with
 > individual /30s), or when the network is native l2 ...
 > in these cases some alignment / coordination between pe and ce
 > configuration is required. you need to know which circuit is
 > connected to which site to end up with a correct, and working
 > configuration.

this too can and has been automated at least in case of atm. you simply
have one-to-one mapping between subinterface numbers and vpi numbers and
then when the ce learns a new label, it knows which subinterface it
belongs to based on its vpi component.

the same can be done with native mpls by using label stacking: the outer
label selects the vpn and the inner label determines a site within that
vpn.  it doesn't matter if a "vnp" has many sites or if it is just a
point to point link.

-- juha

____________________________________________________________________
Get free email and a permanent address at http://www.netaddress.com/?N=1