The MPLS WG Archive

[Yangguang Xu <xuyg@lucent.com>]

Please see further questions below:
 
Chatur sharp wrote:
> 
> It runs on TCP, which provides this garuntee. Incase
> response is not received the TCP times out. Much like
> T301 etc.

Anything can happens. What happens if TCP session is OK, but CR-LDP packets are
dropped some place, for example, buggy CR-LDP code? Are we sure that TCP is
enough? Do we have any requirement for CR-LSP setup time? Any requirements from
service provider?


> A couple of points to remember are :
> 1. Q.2931 is a UNI i/f where message from
>    one user (caller) are carried by the network
>    ( through possibly multiple hps ) to the second
>    user ( receiver).
> 
>    LDP is not like that it is really Peer to Peer.
>    So protection for individual calls is not really
>    required. ( Although it would be desirable for
>    some other purpose )
> 
> 2. Typically TELCO protocols have more reliability
>    redundancy built into the stack than datacom world.
> 
>

First, I should say PNNI.

Second, MPLS is mainly defined for core data network, where reliability is as
important as any traditional Telco network. PNNI or Q.2931 is a little bit too
complicated, however, I think timer is still needed for CR-LSP setup.

Yangguang