Subject: label field!

From: "Andrea Tricco" <[email-masked]>
Date: Tue, 14 Sep 1999 15:03:16 +0200

Hi all,

In draft-ietf- mpls-label-encaps-04.txt at pag 3: ...Label value, 20 bits.

In draft-ietf-mpls-atm-02.txt, in  section 7: ... the label is carried in
the
VPI/VCI field, or, when two ATM-LSRs are connected via ATM "virtual path",
in the VCI field.

How is possible to carry the Label (20 bits) in the VCI field (16 bits)
of ATM header ?

Sorry if the question is stupid.

Thanks in advance.

Andrea.

---

From: Eric Rosen <[email-masked]>
Date: Tue, 14 Sep 1999 09:54:19 -0400

Andrea> In draft-ietf-mpls-label-encaps-04.txt at  pag 3: ...Label value, 20
Andrea> bits.

This draft specifies the encapsulation for PPP and LAN links.

Andrea> In  draft-ietf-mpls-atm-02.txt,  in  section  7: ...  the  label  is
Andrea> carried in  the VPI/VCI field,  or, when two ATM-LSRs  are connected
Andrea> via ATM "virtual path", in the VCI field. 

This draft specifies  the encapsulation for ATM links.   Note that according
to this  doc, the encoding  of draft-ietf-mpls-label-encaps.txt is  not used
for the top label on ATM links.

Andrea> How is  possible to carry the Label  (20 bits) in the  VCI field (16
Andrea> bits) of ATM header ?

I heard  a rumor that ITU  is going to mandate  the use of  a 20-bit VPI/VCI
field for MPLS ;-) ;-)