Subject: RE: mplsLdpEntityTable

From: "Tiruveedhula, Kishore" <[email-masked]>
Date: Fri, 19 Oct 2001 11:01:11 -0400

Hi Joan,
      For example if LSR has 6 interfaces, in which all interfaces uses
platform label space and Generic Labels with one LSR ID and LSR supports 
both DOD and DU modes.
 
 Interfaces 1,2,3 are configured for DOD and interface 4,5,6 are configured
for DU.

                 /----- Session established through interface 1.  By
negotiation, this session can have DU.
                /
   entity 1----/------- Session established through interface 2. By
negotiation, this session can have DOD.
   (DOD)       \
   Platform     \------ Session established through interface 3. By
negotiation, this session can have DU.
   label space
   
   Even though, entity configured for DOD, some sessions can use DU after
negotiation. ( RFC 3036 section 3.5.3)

                 /----- Session established through interface 4.  By
negotiation, this session should use  DU. 
                /
   entity 2----/------- Session established through interface 5. By
negotiation, this session should use DU. 
    (DU)       \
  Platform      \------ Session established through interface 6. By
negotiation, this session should use DU. 
  Label Space

   As per RFC 3036 section 3.5.3,

         If one LSR proposes Downstream Unsolicited and the other
         proposes Downstream on Demand, the rules for resolving this
         difference is:

         -  If the session is for a label-controlled ATM link or a
            label-controlled Frame Relay link, then Downstream on Demand
            must be used.

         -  Otherwise, Downstream Unsolicited must be used.

  In the above entity 1 and 2 have same LSR ID and same Label Space ID zero.

In case of targeted peer configuration.
         
   entity 3---------- Session established by extended discovery for remote
peer A.
   (DU)       
   Platform     
   label space

  entity 4---------- Session established by extended discovery for remote
peer B.
   (DU)       
   Platform     
   label space

  entity 5---------- Session established by extended discovery for remote
peer C.
   (DU)       
   Platform     
   label space

In the above entity 4, 5 and 6 have same LSR ID and same Label Space ID
zero. Is it not possible ?

I think, to distinguish all above entities, EntityIndex can be used. If
EntityIndex can't be used, how to distinguish above all entities ?

Thanks,
Kishore

-----Original Message-----
From: Joan Cucchiara [mailto:[email-masked]]
Sent: Friday, October 19, 2001 2:50 PM
To: Tiruveedhula, Kishore
Cc: Srinivas T M; [email-masked]; [email-masked];
[email-masked]; [email-masked]
Subject: Re: mplsLdpEntityTable

"Tiruveedhula, Kishore" wrote:
> 
> Hi Joan,
> 
> >>      The entry in the entity table is indexed by both mplsEntityLdpIds
> and
> >> mplsLdpEntityIndex.
> >>        Can't we create two entries with same mplsEntityLdpIds with
> different
> >> mplsLdpEntityIndex in the Entity Table to support both DOD and DU
> sessions
> >> using per platform label space on a LSR with same LSR id ?
> >>  mplsLdpEntityIndex  is used to uniquely identify row in the
> >> mplsLdpEntityTable. I think we can have two or more entries with same
> >> mplsEntityLdpIds with different mplsLdpEntityIndex. Is this correct ?
> 
> >This is not a viable solution to the problem --
> 
> Why this is not a viable solution to this problem ? Is there any specific
> reason ?

Hi Kishore,

Perhaps I am not fully understanding what you are trying to do.  The
first
email asked if you could have the per platform label range support both
DOD and DU -- I don't see how this is a viable solution, because LSR A
(entity)
needs to agree upfront with LSR B (peer) as to whether they will create
sessions
DOD or DU, so how could some session support one way, and some support
another way
and how would this be communicated between LSR A and LSR B?

> 
> Even for each targeted peer configuration, one entry need to be created
for
> each targeted peer in the entity table
> with same mplsEntityLdpIds with different mplsLdpEntityIndex in which
> session created by extended discovery method.

The LdpId needs to be unique for an entity (i.e. LSR A).  The
EntityIndex was requested
by the working group for use with something like multi-link PPP.  It
does not mean that this
is a different entity (it means that the same entity needs a way to
differentiate something)
 -- if the LDP ID is the same, then it is the same entity.  An entity
negotiates with a peer
and this is when (according to LDP protocol) they agree on using DOD or
DU as well as the
label range, as well as other info.

  -Joan

> 
> > you will still have only
> >one LSRID and that implies that one session will be capable of both
> >DOD and DU which is not possible with LDP.
> >
> >   Thanks, Joan
> 
> Thanks,
> Kishore