Hi Don,

On Tue, Jan 21, 2014 at 4:32 PM, Fedyk, Don <[email protected]> wrote:

>  Hi Alia
>
>
>
> When I read through  this thread I question data Model that is being
> described.
>
>
>
> If the model reports the TE parameters themselves then you have summaries
> of BW etc.  And you know little about the true resource profile.
>
>
>
> But if the Model supports  something like (forgive the pseudo syntax.)
>
> Object[RSVP-TE Session ID] Ingress Link[i/f ID], Label,  egress Link[i/f
> ID], Label, BW 2 Mb
>
> Object[RSVP-TE Session ID] Ingress Link[i/f ID], Label,  egress Link[i/f
> ID], Label, BW 5 Mb
>
> …
>
>
>
> Then one could construct a much better model of TE parameters.   The
> reason we never did that for TE parameters was because Routing had to
> summarize in order to scale.   Are we planning to limit the I2RS model this
> way too? Or would this TE information be augmented with more detail by some
> other means?
>
>
Good question!  In the context of the information model for topology
produced via ISIS, OSPF, or BGP-LS, I2RS can't really provide more
information than the underlying protocol has.

In general, in the architecture (new draft version in progress), the idea
of a "service" and associated information model for RSVP-TE is there.  In
that context, I can certainly see the above being useful to provide.  We
don't have anyone volunteering yet (that I know of) to write down some
ideas for the RSVP-TE information model...

Regards,
Alia



>
>
> Thanks,
> Don
>
>
>
>
>
> *From:* i2rs [mailto:[email protected]] *On Behalf Of *Alia Atlas
> *Sent:* Thursday, January 09, 2014 6:00 PM
> *To:* Greg Mirsky
> *Cc:* [email protected]; Russell Harrison; Dhruv Dhody; Guanxiaoran
>
> *Subject:* Re: [i2rs] TED extension in topology info model
>
>
>
> (WG chair hat off)
>
>
>
> For those not familiar, the proposed additional attributes are coming from
>
> draft-ietf-ospf-te-metric-extensions-05.  It makes sense to me that the
> topology sub-models would include this type of information.
>
>
>
> Alia
>
>
>
> On Thu, Jan 9, 2014 at 5:57 PM, Greg Mirsky <[email protected]> wrote:
>
> Hi Dhruv, et al.,
>
> I think that your explanation of Residiual BW and BW Utilization fields
> clearly indicates that these, as well as related to timing, are rather part
> of Performance Measurement info and as such depends upon measuring
> instruments. For example, measuring Link Delay use active or passive
> method? If active, what could be size of test packet? Variable or not?
>
> Though PM is very interesting subject, I believe that inclusion of
> dynamically measured in-service performance parameters would only
> destabilize the topology while adding little value. I think that PM is more
> useful on Service rather than Link level.
>
>
>
> Regards,
>
> Greg
>
>
>
> On Thu, Jan 9, 2014 at 2:13 AM, Dhruv Dhody <[email protected]>
> wrote:
>
> *From:* i2rs [mailto:[email protected]] *On Behalf Of *Russell
> Harrison
> *Sent:* 09 January 2014 15:26
> *To:* Guanxiaoran
> *Cc:* [email protected]
> *Subject:* Re: [i2rs] TED extension in topology info model
>
>
>
> Looks ok in concept, but there's a great deal of redundancy in the
> performance info you describe. It seems that only one of the
> residual/available/utilized fields would be needed.
>
> *[DD] Hmmm I disagree. *
>
> *All 3 fields maybe used as they have subtle differences. *
>
>
>
> *Residual BW =  Maximum Bandwidth minus the bandwidth currently
> *allocated* to RSVP-TE LSPs.*
>
> *Available BW = Residual bandwidth minus the measured bandwidth *used* for
> the actual forwarding of non-RSVP-TE LSP packets. *
>
> *BW Utilization = the actual utilization of the link (i.e.: as measured in
> the router including both RSVP and non-RSVP)*
>
>
>
> The other two could be calculated (not to mention, in this context
> residual and available probably mean he same thing.
>
> *[DD] “*residual and available*” are different, as above! *
>
>
>
> THe delay and loss fields are also interesting, assuming good methods to
> measure same are in place...
>
>
>
> -rh
>
>
> Sent from my iPhone
>
> On Jan 9, 2014, at 3:19 AM, Guanxiaoran <[email protected]> wrote:
>
>     Hi ,
>
>
>
> [draft-medved-i2rs-topology-im-01] defines a TED (Traffic Engineering
> Data) component ([RFC5305], [RFC3630]):
>
> <ted-link> ::= <COLOR>
>
>                      <MAX_LINK_BANDWIDTH>
>
>                      <MAX_RESV_LINK_BANDWIDTH>
>
>                      (<UNRESERVED_BANDWIDTH>...)
>
>                      <TE_DEFAULT_METRIC>
>
>                      [<srlg-attributes>]
>
>
>
> Besides the factors proposed in that document, other factors such as
> latency, limited bandwidth, packet loss, and jitter
> ([draft-ietf-isis-te-metric-extensions-01],
> [draft-ietf-ospf-te-metric-extensions-05], [draft-wu-idr-te-pm-bgp-03]),
> are all important that need to be taken into account in the topology info
> model.
>
>
>
> For example, shall we extend the TED component (i.e. including network
> performance information ) as follows:
>
> <ted-link> ::= <COLOR>
>
>                      <MAX_LINK_BANDWIDTH>
>
>                      <MAX_RESV_LINK_BANDWIDTH>
>
>                      (<UNRESERVED_BANDWIDTH>...)
>
>                      <TE_DEFAULT_METRIC>
>
> <TE_Performance_Info>
>
>                      [<srlg-attributes>]
>
>
>
> <TE_Performance_Info> ::= <Unidirectional Link Delay>
>
>                                                    <Min/Max Unidirectional
> Link Delay>
>
>                                                    <Unidirectional Delay
> Variation>
>
>                                                    <Unidirectional Packet
> Loss>
>
>                                                    <Unidirectional
> Residual Bandwidth>
>
>                                                    <Unidirectional
> Available Bandwidth>
>
> <Unidirectional Utilized Bandwidth>
>
>
>
> What do you think?
>
> *[DD] Maybe we should have -  [<TE_Performance_Info>] making it optional?*
>
>
>
> *Regards,*
>
> *Dhruv*
>
>
>
>
>
> Regards,
>
> Ran
>
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