Subject: questions on LDP session initialization

From: "Tong Wu" <[email-masked]>
Date: Tue, 2 Jan 2001 23:27:12 +0800

Hi,

In 3.5.3. of draft-ietf-mpls-ldp-11.txt, it is said that
    "
        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
  
    "

Are there any deep reasons to distingish the case of ATM/FR from others'?
Is it just becaue of the considerations of label-merging difficulties in ATM or FR  networks?

Thanks a lot in advance.

Best Regards,
Wu, Tong