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Re: Bandwidth modification in GMPLS
Manoj,
There is a difference between
1) modifying the bandwidth of a connection and
2) replacing the connection by a different connection.
Add 2) A VC-3 connection is a connection in a VC-3 network layer, whereas a VC-4
connection is a connection in a VC-4 network layer. These network layers are
independent, and as such you can only replace a VC-3 connection by a VC-4
connection by releasing the VC-3 connection and requesting to set up a VC-4
connection.
Add 1) You can modify the "bandwidth" of a group-connection (i.e. NVC(*) or MT
>= 1), by adding/removing connection members. If this group-connection supports a virtual concatenated trail (VC-n-Xv, ODUk-Xv) then the supported client link's bandwidth is modified as a result.
Example: Consider VC-4-Xv trail between nodes X and Y which
supports an Ethernet link between these two nodes. When X is
increased from 4 to 5, the Ethernet link bandwdith is increased
from 600 Mb/s to 750 Mbit/s.
Assume that the VC-4-Xv trail is supported via two diverse
routes (X - A - Y and X - B - Y), each providing two VC-4
connections. Then the bandwidth modification will increase
the number of connections on one of the two routes; e.g. the
route via A. The associated traffic parameters will be:
- Connection X - A - Y traffic parameters
* Before increase: ST=6, RCC=0, NCC=0, NVC=0, MT=2, T=0
* After increase: ST=6, RCC=0, NCC=0, NVC=0, MT=3, T=0
- Connection X - B - Y traffic parameters (unchanged)
* ST=6, RCC=0, NCC=0, NVC=0, MT=2, T=0
What is needed is a MODIFY request which allows for an identified connection to
modify the MT value.
(*) Note that the parameter NVC is interpreted as to represent the number of
components in a virtual concatenated signal connection... in this example NVC=4
and grows to NVC=5. As the virtual concatenated signal is transported via two
routes, each having half of the member connections, I have the impression that
MT is the parameter to use.
Or to turn this around and look at the source for the bandwidth modification
first, we may assume that over the e.g. Ethernet UNI the call controller
(G.8080) at the network side receives a request to increase the enthernet link
from 600 to 750 Mbit/s. The call controller then decides to support this
ehternet bandwidth modification request by means of a modification of the
group-connection via route A... it then issues a connection modification request
for this group-connection... etc.
Add 1) True bandwidth modification of an individual connection is possible for
e.g. ATM VP, ATM VC and MPLS connections. As long as the ATM VP, ATM VC or MPLS
links (G.805) over which the connection is transported have spare capacity, the
bandwidth of an individual VP, VC or LSP can be increased.
Regards,
Maarten
manoj juneja wrote:
>
> Hi All,
> If the bandwidth modification is not supported by GMPLS then
> it should be clearly mentioned in the drafts (at least the architecture
> draft). Please see the attached mail for reference.
>
> I am still not clear whether GMPLS supports SE-style of reservation.
> My original question related to SE-style of reservation was and I didn't
> get any reply on the mailing list :
>
> " I have a doubt related to SE style of reservation in GMPLS. As
> in RSVP-TE, multiple senders can share the reservation but they can be
> assigned different labels to distinguish different senders from one
> other.
> In GMPLS, as the label itself is a resource on the link, it means that
> if there are multiple senders in the same session sharing reservation,
> they should be assigned the same label. They can't be assigned
> different labels or is it that GMPLS does not support SE style of
> reservation ?"
>
> Please correct me if I am missing something.
>
> Regards,
> manoj.
>
> >From: Maarten Vissers <mvissers@lucent.com>
> >To: manoj juneja <manojkumarjuneja@hotmail.com>
> >CC: ccamp@ops.ietf.org
> >Subject: Re: Bandwidth modification in GMPLS
> >Date: Fri, 30 Nov 2001 11:45:25 +0100
> >
> >Manoj,
> >
> >manoj juneja wrote:
> > >
> > > Hi All,
> > > Is it possible to modify/increase the bandwidth of an existing
> >GMPLS
> > > tunnel ? I mean to say if I establish a VC-3 SDH LSP, will it be
> >possible to
> > > increase the bandwidth to say VC-4 ?
> >
> >No, this is not possible.
> >
> >Regards,
> >
> >Maarten
> >
> > >
> > > Should the new request be considered independent of previous one ?
> > >
> > > Regards,
> > > manoj.
> > >
> > > _________________________________________________________________
> > > Get your FREE download of MSN Explorer at
> >http://explorer.msn.com/intl.asp
> ><< mvissers.vcf >>
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
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