Subject: PWE3 requirements draft, version 5

From: "Xipeng Xiao" <[email-masked]>
Date: Mon, 17 Mar 2003 21:34:09 -0800

A new version of the PWE3 requirements draft is available for review at:
http://www.cse.msu.edu/~xiaoxipe/pwe3/draft-ietf-pwe3-requirements-05.txt
 
Comments from the last last-call are all considered.  Changes made in this version are:
 
1. The Fragmentation section is re-worded. The original term "SAR" is replaced.
2. The Maintenance section is rewritten.  
   i. How to handle control messages of the native service is now clearly specified;
   ii.  The need for PE-generated maintenance messages, when they are needed, and how to generate and process them at the PEs, are discussed.
3. The Inter-domain section is re-worded.
 
Comments are welcome!
 
XiPeng

---

From: Mustapha Aissaoui <[email-masked]>
Date: Wed, 19 Mar 2003 12:19:33 -0500

Hello XiPeng,
thank you for this update. This revision looks much better than the
previous one. I however have last comments below which hopefully
will help make the document clearer.

Regards,
Mustapha.
----------------
Section 5.2: there is an overlap between this section and section
5.3. In section 5.2, there is also a case where a PE has to generate
native maintenance messages.  I think the confusion does not help in
understaning what is required for emulated service OAM.
I would like to suggest that we restructure these 2 sections as
follows:
- Section 5.2 will deal with the "normal" operation of the emulated
service. That is, the ability to tranparently carry end-to-end
native maintenance messages between CEs (e.g., ATM OAM), and the
ability to properly terminate and respond to link based maintenance
messages (e.g., FR LMI or ATM ILMI) on a CE-PE link.
- Section 5.3 will deal with the fault scenarios. That is what to do
when a failure occurs in a CE-PE link, or between PEs, and how to
interoperate the defect states of the PW maintenance and the native
service maintenance.

Section 5.3: paragraph 8, last sentence says: "If a PE needs to
generate and send a maintenance message to a remote PE, the
maintenance message MUST be sent via the control plane, not via the
PW"
Where does this requirement come from? This is too restrictive. We
should allow the option to send a maintenance message over the PW.

Section 9: second paragraph is still confusing. I think we want to
say that "the QoS objectives for the emulated service need to be
compatible but not necessarily identical to that of the emulated
service". I prefer the word "compatible" because this tells me the
if the native service was a real-time CBR service,  I can select a
real-time emulated service.

----------------------
> Xipeng Xiao wrote:
>    ii.  The need for PE-generated maintenance messages, when they
> are needed, and how to generate and process them at the PEs, are
> discussed.

---

From: "Xipeng Xiao" <[email-masked]>
Date: Wed, 19 Mar 2003 10:21:43 -0800

Mustapha,

Thank you for your comments!  One response below.

 > should allow the option to send a maintenance message over the PW.

A maintenance message is a control plane thing.  It has to stay inside the control plane.  

We will consider your other suggestions.