Re: [L2tpext] [PWE3] An error in RFC 4446 "IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)"

[Jiang Yuan-long <yljiang at huawei.com>]

Neil,

 

Thank you for your reply.

As Himanshu said in the last email, 0x000B is actually the PW type for IP,

rather than L2TP PW type for IP. So I believe it is also feasible for MPLS-TP.

 

I agree with you that there is some difficulty for MPLS label stack to

operate in the same manner as client/server layering model, but an adaptation

layer such as PW functions now is indispensable.

 

 Best Regards

Yuanlong Jiang

 

 

 

----- Original Message -----

From: neil.2.harrison at bt.com

To: yljiang at huawei.com ; pwe3 at ietf.org

Cc: l2tpext at ietf.org

Sent: Wednesday, August 19, 2009 4:16 AM

Subject: RE: [PWE3] An error in RFC 4446 "IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)"

Hi Yuanlong Jiang,

 

Where you said below:

"I also wonder whether we should define a PW type for IP payload so that everything on PW is possible"

 

This is precisely what a key consequence of MPLS-TP is, ie in the LDP spin of MPLS we had to define PWs (one reason being that LDP requires that IP traffic units can run native in the DP with MPLS traffic units), but given we can't have IP in the MPLS-TP DP and we can't have LDP mp2p merging constructs in MPLS-TP anyway (the latter point is all about resource management determinism) then the original driver for PWs is gone.....just a fact.  So now everything is a PW and nothing is a PW....that is, we just have clients (any) of MPLS-TP.

 

We still have a tricky issue with the S bit that is not fully understood IMO yet (S bit => sublayering, as opposed to true client/server layering), which is also related to the important topic of being able to do MPLSoverMPLS as a proper client/server relationship.

 

So what you point out below will be the case in MPLS-TP anyway (though I'm not sure everyone is comfortable with the acceptance of this fact yet)

 

regards, Neil

 

---

From: pwe3-bounces at ietf.org [mailto:pwe3-bounces at ietf.org] On Behalf Of Jiang Yuan-long
Sent: 18 August 2009 14:01
To: pwe3 at ietf.org
Cc: l2tpext at ietf.org
Subject: [PWE3] An error in RFC 4446 "IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)"

Hi, all:

I came accross an error in RFC 4446 "IANA Allocations for Pseudowire

Edge to Edge Emulation (PWE3)".

 

In Sec 3.2, it says:
"   0x000B  IP Layer2 Transport                              [RFC3032]"

 

it should be:  
   0x000B  IP Layer2 Transport                        [draft-ietf-l2tpext-pwe3-ip]
  
The same problem also exists in web page version http://www.iana.org/assignments/pwe3-parameters.

I wonder how about the status of this expired WG draft, will any more work

continue on this document or just expired as it is? 
I also wonder whether we should define a PW type for IP payload so that

everything on PW is possible.
Any comments?
  
   Thanks,
Yuanlong Jiang