[afnog] QoS/TE

[Mark Tinka]

On Wednesday 18 January 2006 19:17, Jim Forster wrote:

> I would tend to agree, although most of the thought and
> analysis has been done for places with fiber based
> cores.   In these places the cost of additional
> bandwidth for core networks is generally cheaper than
> additional bandwidth for access networks.   In Africa
> it's conceivable that the access networks could be
> cheaper bandwidth through various wireless technologies
> than the cores/backhauls which will only slowly move
> off satellites to terrestial fiber and high speed
> wireless trunks.

In countries with reliable country-wide infrastructure, 
copper or fibre access will be used for core 
connectivity; but penetration will vary with costs based 
on amount of distance covered and/or amount of capacity 
required, as in most cases, a single service provider 
(*elco) will provide country-wide access.

There are cases where terrestrial/wireless connectivity 
disappears somewhere inland (terrain, no business motive, 
e.t.c.), so satellite is used - but these have seen more 
direct connectivity to a transit provider and less 
upstream/downstream connectivity to the core, making a 
case for QoS.

> QoS is very frequently over-engineered, but if has a
> place it's on the bottleneck links; I'm suggesting that
> the bottleneck links may be in a different segment of
> the network, depending on the economics.

Yes; edge and border/upstream. Some customers with clue 
will deploy QoS features on their CPE, and ask the ISP do 
the same on the CPE-facing edge routers - ISP charges a 
small fee, customer is happy, all win.

At the border, well, various bandwidth manager vendors, 
including vendors J and C have features.

So this leaves the core - if you've over-engineered your 
core (which is very easy to do once the economics are on 
your side), assuming infrastructure availability, and you 
see about 65% utilization (or perhaps even more)... QoS?

Mark.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 827 bytes
Desc: not available
Url : http://listserv2.cfi.co.ug/pipermail/afnog/attachments/20060119/a03307ca/attachment.bin