Subject: setting ER-LSPs

From: Panos Trimintzios <[email-masked]>
Date: Fri, 28 Jan 2000 19:07:17 +0000 (GMT)

Hi everybody,

As far as I have read about the ER-LSPs they reflect 
the administrator's decisions/policies (right?) in 
order (not only) to do TE.
If that is true then could someone use a management
protocol (eg. SNMP) to set an ER-LSP? 
If yes why do we prefer signalling (CR-LDP or extendent RSVP),
If not why?

thanks

Panos Trimintzios
Centre for Communication
Systems Research 
University of Surrey, UK

---

From: [email-masked]
Date: Fri, 28 Jan 2000 16:48:24 -0500

> > Panos Trimintzios wrote:
> > Even if you have decided on the path through the network, it
> > is easier to talk to the LSR at one end of the ERLSP (via
> > SNMP) and instruct it to set up the ERLSP via LDP/RSVP than
> > to talk SNMP to each switch along the path. BTW, the above
> > MIBs allow you to take both approaches.
> > 
> > Cheenu
> > 
> 
> 1. Why it is "easier" to talk to one end of ER-LSP (via SNMP)
>    and then signal the setup, since the signaling requires
>    (for both CR-LDP and ext-RSVP) to go all the way to the other 
>    end of the ER-LSP and then back to where it began, and 
>    possibly again notify (via SNMP) the administrator process.
>    Is there any work that has been done to test this? 
>    Isn't more complicated to use [SNMP + (LDPorRSVP)] than to
>    use only [SNMP]?

The amount work to be done to configure the LSRs along the path
is probably the same in either case. I meant "easier" from the
point of view of the one writing the network management application
since invoking a signaled setup involves one SET request and
talking to all the individual LSPs along the path involves
multiple SETs.

> 2. Someone could argue against the above by giving details 
>    about the "weaknesses" of SNMP (eg not suitable for real-time
>    operations, unreliability(UDP) etc). Comming  back to 
>    my original question we can see that I have asked if we
>    could use a management protocol, not necessarily SNMP,
>    but another more suitable, lets say XXXP (one example that 
>    comes to my mind is COPS-PR).
>    So I repeat my argument/questions in 1. , by replacing SNMP 
>    with XXXP.

This wasn't what I meant.

Cheenu