[asterisk-users] ADSL routers with integrated SIP QoS for otherdevices

[Dan Austin]

Andrew wrote:
> On Saturday 28 April 2007 11:22 am, Chris Bagnall wrote:
>> Thanks to all who replied to my thread a few days ago "SIP devices
with
>> packet loss tolerance". One of the suggestions that came out of that
thread
>> was to replace routers at users' premises with ones that support QoS.

> Sangoma S518 (internal PCI) on a Linux box with iproute2/iptables/tc
or BSD 
> with pf.  These are the best solutions, IMO.
I was just about to reply with the same recommendation.  A SFF chassis
with
2 PCI slots could host one S518 and a PSTN interface.  These units
typically
have built-in ethernet and some have built-in wireless.  I still have my
fingers crossed that Sangoma will offer an ADSL daughercard for the
A200.
That would make for a perfect combination in a SFF chassis...

> The latest Linux kernels also have SIP connection tracking/matching,
so it 
> should be possible to mark packets and prioritize based on iptables
matching.  
> I have not done this just yet, as the latest 2.6.20/2.6.21 kernels do
not 
> play nice with the wanrouter drivers.

> (note: there was a recent patch to 2.6.20.4 which apparently has much
better 
> SIP matching, and has been tested successfully with Asterisk.  I have
not 
> tested it yet, and the iptables guys have rejected the patch as their 
> direction for packet matching is shifting significantly in the near
future.  
> It can be found at 
>
http://thread.gmane.org/gmane.comp.security.firewalls.netfilter.devel/18
860.)

> I'm still looking for a miniPCI ADSL chipset that Linux can use, or an

> actual "raw" ADSL non-PCI chipset that I can design into an embedded
system.  
> If anyone has any leads, please don't hesitate to contact me!
Good luck and let us know if you find one.  The manufacturers of the
XDSL
chipsets seem to be even worse than the video card companies when it
comes
to OSS.

There's a project on SF called OpenADSL that was working to make common
XDSL chipsets work under Linux.  The project appears almost dead with a
developer post every 6~8 weeks, but that might be a good place to start
Looking.


> If you're curious, I have my rc.tc script for Linux up on 
> http://mixdown.ca/~andrew/rc.tc.  It's loosely based off of
wondershaper, but 
> works much better, IMO.  It does host-based prioritization for VOIP,
puts 
> mail just underneath bulk traffic, and P2P beyond that (if you have
the p2p 
> connmark stuff set).  I can completely saturate DSL links with the
S518 with 
> this config without appreciable VOIP degradation.
I'm using something similar.  The missus can talk to her mother (in
rural Japan)
over IAX while I am using a IPSEC tunnel to work, and doing heavy
downloads.

> Even without an S518, this script works well with external ADSL/cable
modems.  
> You may have to play with the upload rate; some cheap ADSL modems will

> start "blocking" your upstream traffic beyond as little as 50% of the 
> upstream rate.