|
Hi all,
I am also wondering what is PCE.
Can PCE give a route or routes to someone
unsolicitedly without path computation request (PCReq) from
PCC?
Thanks
Fatai
Advanced Technology Department
Wireline Networking
Business Unit
Huawei Technologies Co., LTD.
Huawei Base, Bantian,
Longgang,
Shenzhen 518129 P.R.China
Tel: +86-755-28972912
Fax:
+86-755-28972935
----- Original Message -----
Sent: Monday, October 19, 2009 9:20 PM
Subject: Re: [Pce] I-D
Action:draft-bao-pce-pre-configured-routing-00.txt
Hi Cyril,
Fine with what you say, but...
We did
consider allowing the PCE to push unsolicited routes to the PCC. We
decided
this was not actually the correct information or processing flow.
The
point is that a "new route" is only available if a new computation
is
performed. But the PCE only performs computations on demand. How would
it
know that the network event should cause it to perform a new
computation,
and how would it know whether the newly computed route was
wanted by the
PCC.
However a third party tool (for example, the NMS,
or the VNTM, depending on
the scenario) should be able to perform this
function that is heavily
associated with local network and per-LSP policy.
In these cases, it is the
management entity that is requesting path
computations as the PCC, and it
will push those paths to the LER according
to policy.
Of course, the LER could be the PCC and could request the
paths, but it is
less likely to be in control of the necessary triggers.
This behavior is
actually very similar to what you might expect for
reoptimization.
Cheers,
Adrian
----- Original Message -----
From: "Margaria, Cyril (NSN - DE/Munich)" <cyril.margaria at nsn.com>
To:
"Adrian Farrel" <adrian at olddog.co.uk>; <Bao.Yuanlin at zte.com.cn>;
<fu.xihua at zte.com.cn>; <xie.gang at zte.com.cn>
Cc: <pce at ietf.org>
Sent: Monday, October 19,
2009 1:39 PM
Subject: RE: [Pce] I-D
Action:draft-bao-pce-pre-configured-routing-00.txt
Hi,
I
think the term pre-configured route is a bit misleading, I understand
the
scenario as the PCC ask for 3 routes, the first one will be
signaled, the 2
other kept in case a failure happens on the first route.
If I am not
misunderstood this can be achieved by using the svec with 3
time the same
endpoints and bandwidth.
Regarding the indication that a route has
changed, the PCE could send a
PCRep with RRO (not allowed in rfc5440) and
ERO containing the new Path,
but what should be the request id of the
PCRep?
In addition the PCC could also be aware that the route failed
and
request a new Path computation for the failed path.
In this
context I do not see the need to have a new flag in the RP
object for this
use case.
Best Regards
Cyril Margaria
-----Original
Message-----
From: pce-bounces at ietf.org
[mailto:pce-bounces at ietf.org] On Behalf Of
ext Adrian Farrel
Sent:
Monday, October 19, 2009 1:29 PM
To: Bao.Yuanlin at zte.com.cn; fu.xihua at zte.com.cn; xie.gang at zte.com.cn
Cc: pce at ietf.org
Subject: Re: [Pce]
I-D
Action:draft-bao-pce-pre-configured-routing-00.txt
While this is
a reasonably well-written draft, I don't see that it adds
anything to what
we already have in the core RFCs.
In section 4.3 you
have...
There are two options
for PCE to
send pre-configured route as follows:
PCRep is used to respond
route computation result naturally. If it
is used to
send pre-configured route, a new flag SHOULD be defined to
indicate the route carried is pre-configured route.
Two
questions:
1. What is the other option? You only list one option.
2. Why
do you need a flag to indicate that a route is pre-
configured? Why does the PCC care how the route was
derived?
You slighlty answer question 2, in section 5.1 where you
say...
When PCC requests pre-configured
route
...but why would the PCC ask for a pre-configured route? It just
wants a
route. If there is a policy to be applied by the PCE in
selection of the
route, this should be indicated using the normal
policy functions. If
there
is an objective function/algorithm to be
applied in selecting the route,
this should be indicated using the OF
object.
So I think that you don't need the pre-configured route
flag.
Cheers,
Adrian
_______________________________________________
Pce
mailing list
Pce at ietf.org
https://www.ietf.org/mailman/listinfo/pce
_______________________________________________
Pce
mailing list
Pce at ietf.org
https://www.ietf.org/mailman/listinfo/pce
|
