[Asterisk-Users] (Semi-OT) QoS Question FTP Living with Asterisk

[Kristian Kielhofner]

Steve Totaro wrote:
> I have searched google and came up with too many options and packages 
> that may or may not work for my needs, most articles seem to be for 
> setting up routers.  Maybe someone on the list can give me some better 
> insight.
> 
> I have monitoring turned on my "shift eight (tm)" (Asterisk ;-)) box for 
> all calls.  We have over one hundred agents and tons of recordings in 
> wav format.  I also have a cron job that runs a script to mux the in and 
> out files and ftp them to a NAS device and it runs every five minutes.
> The NAS device and the * box are both directly connected to a Cisco 
> Gigabit switch.  I have had complaints of calls fading in and out and 
> also cutting off.  After reviewing the recordings, some of these 
> complaints seem valid and I suspect the sheer bandwidth of the FTP 
> traffic is causing the issues.  I also run nagios checks on the box and 
> get ping warnings on a regular basis.
> My question is, how can I throttle the FTP (Standard with dist) 
> transfers using out of the box CentOS4.3 (or any easy to use, low 
> learning curve package)?  I thought about FTPing the files at less 
> frequent intervals but that just makes the issue less frequent but last 
> longer.
> I would like to accomplish throttling FTP on the Linux box with a 
> solution that is not too elegant since this is a production machine in a 
> busy call center.  If I cannot do it on the * box I guess my next step 
> is to see if the Cisco Gigabit switch has any QoS functionality.
> Thanks,
> Steve

Steve,

	Now for the fancy solutions:

1)  Try enabling NAPI interrupt handling for your ethernet card.  Some 
people report that it reduces interrupt load while increasing transfer 
speed by %85 - %100 (on the same processor, with the Intel e1000 driver 
and a good Intel NIC).  I haven't tried it yet, but that is what I have 
read...

2)  AstShape:

http://www.krisk.org/astlinux/misc/astshape

3)  AstShape and Cisco:

http://www.krisk.org/astlinux/misc/astshape

	Configure the Catalyst to map packets with IP TOS 0x10 and 0x18 into 
the second highest priority (the highest priority is reserved for 
"network control messages").  Either whatever the Cisco has or 802.1p 5 
(the highest priority for "end user" traffic).

	At gigabit speeds QoS configured like this will probably just waste CPU 
time (on both the machine and the switch) while not being very 
effective.  Try my simple suggestions from my previous post first! :)

-- 
Kristian Kielhofner