Subject: Vlan translation

From: "Bala S. Venkata" <[email-masked]>
Date: Sun, 19 Feb 2006 21:28:28 -0800

HI,

A ldp-vpls newbie question:

I have two customer sites which use different vlan's (say ids 601 and 602).
Suppose I want to connect them should I necessarily set up a vpls between them ?
If so the PE access ports should be access port ? What would be the FEC VC type
of the vpls (ethernet/ethernet-vlan) ? 

      +-------+     +------+               +------+      +-------+
      |  CE   |-----|  PE  |----..mpls..---|  PE  |------| CE    |
      |site1  |     |dev A |       core    |dev B |      | site2 |
      |vid:601|     |      |               |      |      |vid:602|
      +-------+     +------+               +------+      +-------+

Can I add a third site to participate in such a vlan translation ?

Thanks !

/bala

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From: "Rajesh Pandey" <[email-masked]>
Date: Mon, 20 Feb 2006 16:49:17 +0530

Hi Bala,

Find my answers inline:

>> As far as VLAN translation is concerned, you do not need to have VPLS for
that. It can be implemented simply on top of layer 2. But, if you are
talking about VPLS CEs, where multiple customer sites talking in different
VLAN to the MPLS core; you need to have VPLS between them. The VLAN
information may typically be sent in the FEC-TLV for VLAN translation and L2
rules can applied at CE-PE.

If so the PE access ports should be access port ?

>> Need not be.

What would be the FEC VC type

>> I think using the PW type depends upon the kind of VPLS instance (type
port<->port, port-vlan<->port-vlan) and not on you want to do the VLAN
translation or not. Typically, if you want to carry the .1Q tag across the
MPLS core you would likely to use Ethernet VC-type and vice-a-versa.

>> Yes. Provided, you do the same thing for the newly connected site (making
PW to the new site from other two sites.)

Regards,
Rajesh

Thanks !