asterisk users - Feb 2006 - Bandwidth: to seperate or not to seperate

Hi everyone,

RE: Bandwidth.  We have an asterisk server sharing bandwidth with other 
[web] servers in cabinets that we rent in a large data-center and all is 
working fine.  But I'm concerned that web traffic could affect the VoIP 
quality (my tests so far haven't showed this [yet!].  Currently I'm 
running a server with Netfilter (iptables) between all the servers and 
the Internet with Forward rules and I'm also including a
"wondershaper"
type QoS ruleset with TC to priortise the outgoing VoIP traffic (I say 
outgoing because this is really the only thing I can shape on the 
connection as far as I can see).

My choice, going forward, is to either buy more bandwidth and magically 
implement better QoS or the other option is to bring in a separate patch 
cable, with separate bandwidth, and a different IP address range 
directly to the asterisk and dedicate bandwidth to it and it alone.

In a way the sharing of bandwidth with QoS would appear to be the better 
value option but I can't see that the TC QoS can really be up to the 
task (again partially this is because I can only control the outgoing 
traffic shaping - there is nothing I can do about the incoming traffic 
flooding the bandwidth).

But obviously the data center has fully operational bandwidth shaping to 
their clients (me!) - or bandwidth "throttling" might be the better 
description as they limit my bandwidth to what I buy from them so by 
buying the separate bandwidth I'd just be relying on their bandwidth 
shaping rather than trying to do it myself.

Does anyone out there know the correct answer to this?  I'm sure many 
people must have come up against this before?

Thanks for any help!

Derek

-- 
Derek Conniffe
Rivertower Ltd
DID Number: 01 440 1806 (International: 00 353 1 440 1806)
Ireland: (Local) 01 440 1800
United Kingdom: 0870 068 2368
International: 00 353 1 440 1800
Derek Conniffe Mobile: 086 856 3823 (International: 00 353 86 856 3823)
Fax: 01 201 0085 (International: 00 353 1 201 0085)
Email: Derek@rivertower.ie
Web: http://www.rivertowerhosting.com

Inline...
> RE: Bandwidth.  We have an asterisk server sharing bandwidth with other 
> [web] servers in cabinets that we rent in a large data-center and all is 
> working fine.  But I'm concerned that web traffic could affect the VoIP
> quality (my tests so far haven't showed this [yet!].  Currently I'm
> running a server with Netfilter (iptables) between all the servers and 
> the Internet with Forward rules and I'm also including a
"wondershaper"
> type QoS ruleset with TC to priortise the outgoing VoIP traffic (I say 
> outgoing because this is really the only thing I can shape on the 
> connection as far as I can see).
If your web server is oriented around simply serving up static pages with
no one "uploading" data to it, then the majority of the web traffic
will
be outbound traffic. (eg, user clicks on a link, small amount of inbound
traffic to communicate that click, followed by lots of outbound traffic
reppreenting the new page(s) to be viewed.)

The wondershaper function should prrioritze that mix of traffic just fine.
 
> My choice, going forward, is to either buy more bandwidth and magically 
> implement better QoS or the other option is to bring in a separate patch 
> cable, with separate bandwidth, and a different IP address range 
> directly to the asterisk and dedicate bandwidth to it and it alone.
The above is certainly possible, but probably not the most cost effective
use of total bandwidth. Based on the words provided, the single link
bandwidth should be sized to handle the maximum number of voice channels
to be used plus a small amount for web traffic. 
 
> In a way the sharing of bandwidth with QoS would appear to be the better 
> value option but I can't see that the TC QoS can really be up to the 
> task (again partially this is because I can only control the outgoing 
> traffic shaping - there is nothing I can do about the incoming traffic 
> flooding the bandwidth).
Help us understand exactly what this "incoming traffic flooding the
bandwidth" is suppose to mean. Are you running something else besides web
and voip through this link?  If not, then what is "flooding" your 
bandwidth?