Re: [alto] draft-yang-alto-path-vector-03 and cost-map service

Hi Hans,

Is it possible to compress the cost map by using routing state abstraction?
I think it is a potential solution.

Another solution may be to add a proxy layer to compress and decompress
ALTO protocol messages. It will reduce the communication time and not
change the implementation of ALTO servers and clients. But compression and
decompression will increase extra processing time.

We haven't test such large-scale networks, but it is indeed a problem which
need to be handled.

Best,
Jensen

On Thu, Aug 11, 2016 at 9:08 PM, Hans Seidel <hseidel@benocs.com> wrote:

> Hi Richard, all,
>
> after the ALTO session in Berlin, we shortly talked with Ingmar about the
> impact of path-vector on the size of cost maps especially in large-scale
> networks.
>
> I carried out some tests with path-vector cost maps based on our data. Our
> cost maps are already very large but path-vector maps are about three times
> larger (~50 MB vs. ~150 MB in uncompressed state). In average we have round
> about 4 hops between two PIDs which leads to an average path-vector of the
> same length. ECMP was not considered in the test but it will certainly
> further increase the size of the map.
>
> Our idea to reduce cost map size is to provide topology information, e.g.
> with the property map presented in the unified-props draft, and let the
> client carry out the path determination. This means, the ALTO server
> provides the network, cost and property map to enable clients to get their
> desired level of detail for the path costs.
>
> I also think this approach can coexist with path-vector cost maps. An ALTO
> server can provide both cost maps with and without path vector and a
> property map providing the topology. This way it is up to the client
> whether it wants to save bandwidth and invests some processing time to
> perform path determination by itself or it fetches the full path-vector
> cost map.
>
> Any thoughts on this?
>
> Cheers
> Hans
>
>
> On 01.08.2016 23:37, Vijay K. Gurbani wrote:
>
>> Folks: As the (draft) minutes [1] of IETF 96 reflect, there was general
>> consensus on adoption of path vector and routing state abstraction
>> documents towards the charter deliverable of graph representation
>> formats in ALTO.
>>
>> The chairs will like to start a call for adoption of the two documents
>> --- https://tools.ietf.org/html/draft-yang-alto-path-vector-03 and
>> https://tools.ietf.org/html/draft-gao-alto-routing-state-abstraction-03
>> --- as deliverables towards the charter item.
>>
>> Note that there remains some ambiguity (in the chair's mind) on whether,
>> once adopted, these will proceed as two drafts or whether they will be
>> merged in one.  The authors of these drafts are urged to provide
>> clarity on the evolution of these documents.
>>
>> The call for adoption runs for two weeks, from Mon Aug 1, 2016 to Mon
>> Aug 15, 2016.  This will be a good time to comment on the list and
>> inform the working group of any issues with adopting these items, or
>> whether the working group was remiss in considering other documents.
>> Please post to the list.  (Even a simple "I support these documents
>> towards charter deliverable" is a good indication.)
>>
>> Thanks,
>>
>> [1] https://www.ietf.org/proceedings/96/minutes/minutes-96-alto
>>
>> - vijay
>>
>
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