Subject: Question on RSTP/MSTP between CE and PE

From: Ravindra Rathi <[email-masked]>
Date: Wed, 11 Jan 2006 16:58:07 +0530

This is regarding following text in draft-sajassi-l2vpn-vpls-bridge-interop-01.txt.

<snip>
For example, when an Attachment Circuit is port-based, then the
bridge module of the PE can operate transparently with respect to
the CEs RSTP/MSTP protocols (and thus no C-VLAN component is
required for that customer UNI). However, when an Attachment Circuit
is VLAN-based (either VLAN mapping or VLAN bundling), then the
bridge module of the PE needs to peer with the RSTP/MSTP protocols
running on the CE (and thus the C-VLAN bridge component is
required).
</snip>

Can anyone explain clearly why PE need not participate in CE's RSTP/MSTP
protocols if attachment circuit(AC) is port based and why it should
participate if AC is vlan based..?

Thanks,
Rathi