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Regarding Label Mapping Advertisements and Label Mapping Release in maritini-trans-10

  • From: "Gray, Eric" <egray@celoxnetworks.com>
  • Date: Mon, 30 Sep 2002 08:55:17 -0400
  • Cc: "Mpls (E-mail)" <mpls@UU.NET>

There is no reason to specify a timer since the implementation

may use one of several approaches to ensure that a reasonable

delay occurs before the label is re-used.  Not all such approaches

are directly timer related.  If an implementation uses a timer, a

reasonable delay can be anything from tens of milliseconds to

tens of seconds.  The actual time that it takes for all labeled

packets to clear the LSP depends on the type of LSP, the

conditions prevailing in the networks along which the LSP exists

and whether or not it is possible for the label release message

to arrive prior to the last labeled packet from the imposition LSR.

 

Eric W. Gray

Systems Architect

Celox Networks, Inc.

egray@celoxnetworks.com

508 305 7214

 

-----Original Message-----
From: Manchanda, Monika [mailto:monika.manchanda@intel.com]
Sent: Monday, September 30, 2002 6:39 AM
To: Mpls (E-mail)
Subject: Regarding Label Mapping Advertisements and Label Mapping Release in maritini-trans-10

 

Hi,

 

 1. The maritini draft section 5.4.1. Label Mapping Advertisements says that

 

"   After a label has been withdrawn by the disposition router and/or
   released by the imposition router, care must be taken to not re-
   advertise (re-use) the released label until the disposition router
   can be reasonably certain that old packets containing the released
   label no longer persist in the MPLS network."

 

According to this the implementation should no re issue the same label for some time period t, which should ideally be the time till all the packets containing the released label reach the disposition router. But how do we determine that what will be the value of t?

 

2. Also the section 5.4.2. Label Mapping Release says that

 

   "In situations where the imposition router wants to restart forwarding
   of packets with sequence number 1, the router shall 1) Send to
   disposition router a label mapping release, and 2) Send to
   disposition router a label mapping request."

 

Here what do we exactly mean by label mapping release and label mapping request?

 

TIA and Regards,

-Monika