Subject: Questions for draft-so-pwe3-ethernet.txt

From: "Mitsuru Higashiyama" <[email-masked]>
Date: Mon, 24 Jun 2002 20:37:47 +0900

Hi,

I have questions for draft-so-pwe3-ethernet.txt.

Q1)  Appendix A describe four modes of Tag add/remove operations.
       Is there more detail explanation in any I-D ?

Q2) It says:
   Mode #4 exists in layer 2 switches, but is not allowed when 
   operating with PW since it does not preserve the user's PRI bit, 
   and in order to save configuration of additional service that can 
   be achieved by other set of configuration. If there is a need to 
   remove the VLAN tag (for TLS at the other end of the PW) it is 
   recommended to use mode #2 with tag2=0 (NULL VLAN) on the PW and 
   use mode #3 at the other end of the PW. 

Why is PWES not allowed remove VLAN tag ? If we runs GVRP on PW,
the switch may send taged and/or untaged pakets on PW ...

Best regards,
Mitsuru

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From: David Zelig <[email-masked]>
Date: Mon, 24 Jun 2002 15:48:30 +0200

Mitsuru,

> the switch may send taged and/or untaged pakets on PW ...
The remark was for a PW that take carry specific VLAN(s) only. In your case
of GVRP I assume that you may want to use the PW as an Ethernet port of a
bridge, and the appropriate PW mode should be "raw", that can carry both
tagged and untagged packets.
Note however that Ethernet PW modes will be probably merge to one type only,
and the action on the packets before it is carried on the PW will be
referred to the NSP function which is not defined by PWE3.

> Mitsuru
David

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From: "Mitsuru Higashiyama" <[email-masked]>
Date: Tue, 25 Jun 2002 20:33:05 +0900

David, Thank you for your answer.

> tagged and untagged packets.

Ohhh. Do you mean PW carry traffic in one VLAN in VLAN mode ?
Why do so ? Does provider surve one VLAN for one customer ?

> referred to the NSP function which is not defined by PWE3.

I see. Who does work to define NSP function ? PPVPN WG ?

Thanks,
Mitsuru
Anritsu Corp.

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From: David Zelig <[email-masked]>
Date: Tue, 25 Jun 2002 17:01:31 +0200

> Why do so ? Does provider surve one VLAN for one customer ?

The original intention of the VLAN mode was to be able to separate a traffic
from a single port to multiple destination, and the VLAN to be used as a way
to identify the different flow. But it does not restrict you from using one
PW to carry multiple VLANs (since it carry the VLAN field too). However
since the PW should be considered as virtual Ethernet port, and the decision
which packets are sent to is based on the NSP function (that still can be
based on the original port and a VLAN, port only, or any combination and
operation on the original packet), a specific VLAN mode is no longer needed.

> 
> > Note however that Ethernet PW modes will be probably merge 
> to one type
> only,
I believe so, but I am not sure to what extent it will be standardized if at
all. PWE3 may however define some guidelines or basic modes as done already
in draft-so and draft-martini.

David