Re: [PWE3] ??: ??: flow label format in draft-ietf-fat-pw-02

[Yong Lucy <lucyyong at huawei.com>]

Steward,

See inline.

Regards,
Lucy
> -----Original Message-----
> From: Stewart Bryant [mailto:stbryant at cisco.com]
> Sent: Wednesday, November 04, 2009 2:26 AM
> To: lucy yong
> Cc: pwe3 at ietf.org
> Subject: Re: ??: ??: flow label format in draft-ietf-fat-pw-02
> 
> Lucy
> 
> Thanks for the email.
> >
> > Hi Stewart,
> >
> > Thank you for the explanation. It is much clear. The reason to use
> > ingress PE and egress PE for this section is that signaling procedures
> > in RFC4447 describes with ingress PE and egress PE. In general, egress
> > PE initiates label mapping message. In your draft, ingress PE sends
> > label mapping message with FL Sub-TLV first. RFC4447 state 2 or 1 way
> > signaling procedure, my impression that your draft states three-way
> > procedures.
> >
> OK - I will fix the naming of the PEs.
[LY] Thanks.
> >
> > The draft states flow label very briefly. Since Flow Label never
> > becomes the top label in label stack, value in the field besides the
> > label field can be any. Is that right?
> >
> Any value except a reserved label (feedback from MPLS chairs and stated
> in the draft). That is a bit annoying in that it makes it more difficult
> to compute the random number, but all sorts of bad things can happen if
> it gets interpreted as a reserved label.
[LY] IF flow label is used, flow label s bit has to be 1. PW label s bit
have to be 0. Flow label EXP and TTL can be any value. Is that right?


> 
> - Stewart