Subject: Doubts, Clarifications requested for draft-ietf-mpls-ldp-ft-00.txt

From: "Manikantan S" <[email-masked]>
Date: Mon, 23 Oct 2000 16:29:19 +0530

Hello Adrian

I read through the draft-ietf-mpls-ldp-ft-00.txt.

I have a few doubts and can you please clarify?

1) In the section 7 Example Use Page 21, in (12) we have

                 LDP Init(n/a,n/a,95)
                 --------------------------->

This should mean that P1 indicates that it has secured
messages with sequence number until 95.

Subsequently we have in (14) 
                       Label Mapping(L2,95,-)
                 <--------------------------- 

Is this correct? Since 95 has been given by P1, is it not
sufficient that p2 provides only the Label Abort message 
which is given next in (14)?

2) In Section 4.4 Page 12, Second Paragraph. "Hold Timer"
has been mentioned. I am not sure of this "Hold Timer".
Is this the Hello Hold Timer (Section 2.5.5 in ldp-11 draft)?

3) Does 
     "The Hold Timer for an FT LDP Session SHOULD be ignored while the FT
      Reconnection Timer is running" mean that the hello
messages need not be expected from the Peer during the
Reconnection time?

4) I am not clear with the advantage meant in the statement
   "This ensures that network resources are not permanently
   lost by one LSR if its LDP peer is forced to undergo a cold start."
in page 8. 

My confusion is, when a LDP Peer P1 is made to undergo a 
cold start, the TCP session will be initiated again 
with "FT Reconnect Flag set to 0". This will cause the other
LDP Peer P2 to release all the information. 

5) What should be done in case of receipt of a "FT ACK Sequence
Error"? This is generated by a Peer P1 to P2 when it receives
an out of sequence ACK from P2. 

6) When do we generate Notification with Status code
   " FT Sequence Numbers Exhausted"

7) It has been mentioned (very clearly) in the second
paragraph in Section 4.4, that the Reconnection timeout is
an implementation choice. Will it be possible to indicate
the possible Reconnection timeout value?

8) Let P1 and P2 are two LDP Peers. Let us assume 
   that P1 has transmitted a set of label requests
   to P2. Can P2 provide a reply to one of the label
   request messages LRQ1 from P1, without containing FT 
   ACK TLV? and if such a message is received by P1
   can P1 assume that the FT sequence number provided in 
   LRQ1 is secured at P2?

Thanks in advance
with best regards
Mani
-----------------------------------------
S.Manikantan
Future Software Limited
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Nandanam, Chennai, India.
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email          : [email-masked]
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