[Asterisk-Users] Router with QoS recommendations

[Bruno Hertz]

tim panton <tpanton at attglobal.net> writes:

> On 4 Apr 2005, at 09:25, Shaoul Jacobson - TELLINK wrote:
>
>> Hi,
>>
>> QoS is nice (and important) but only works within a FULLY controlled
>> end to
>> end link.
>> Inside a BIG enterprise LAN, on leased lines its OK.
>> Using end to end MPLS should also be ok
>> Mind that some provider sell MPLS but it is not their own MPLS end
>> to end.
>> Going from one provider on MPLS to another on MPLS, you lose all the
>> benefits. No control.
>> Using the World Wide Wait (Internet) it will not help.
>>
>> A waste of money.
>> My 2 cents.
>>
>
> I'm not sure I totally agree. It is also useful if you control the
> narrowest pipe.
> Take the example of several sub-offices joined to a head office PBX over
> 'public' ADSL lines. Let's say the company buys all the ADSL lines
> from the
> same provider.
> In such a set-up, the uplink side of the sub-office ADSL links are
> likely to be the main bandwidth limit.
> A well configured router there will slow outgoing email etc to preserve
> the quality of current VOIP sessions.
>
> Sure, the provider may have internal bandwidth constrictions, but
> they are unlikely to kick in before the 256k up channel of
> a typical ADSL.
>
> Oh, and, the web and the internet are not the same thing.
> Think like that and you'll forget mail. Which is a huge bandwidth
> consumer, and can stand being delayed by a second or
> two.
>
> Tim.
>

I agree, especially qos on upstream might be beneficial, and surely
is in a cable modem setup. E.g. my modem has a 10 Mbit LAN interface,
but uplink is limited to 256Kbit. So when I have many things
going out, uplink will be much sooner saturated than the LAN link,
and cable modem buffers run full leading to looong latencies and
maybe even package loss. Putting a router before the modem shaping
the upstream traffic solves that problem.

Regards, Bruno.