[asterisk-users] Problems with the voice quality under load

Mordechay Kaganer mkaganer at gmail.com
Mon Mar 2 11:32:08 CST 2015


Hi, really thanks for all the relies :-)

Here's my answers:

On Mon, Mar 2, 2015 at 5:56 PM, Ron Wheeler <rwheeler at artifact-software.com>

> Have you done the math for the network connections? BTF and external
> What bit rates for the sound?
> What codecs?
> How are calls coming in - SIP - analogue
> Disks OK(low IO per second)? Caching working OK?

There's no problem with network speed - we have 3 port bonding of 1G
connections on each server and 1G external cross connect to the SIP
providers (which are located in the same server farm). Even single 1G link
is sufficient for more than 5000 calls with G711.

All disk IO is off-loaded to the central server with NFS and as far as i
can see, the load is low. In most cases, the people listen to the same
files and caching is OK - each server has 32GB of RAM most of it is used
for caching.

We are connected to several SIP trunk providers. All the setup is SIP only.
The codec is G711.

On Mon, Mar 2, 2015 at 6:02 PM, A J Stiles <asterisk_list at earthshod.co.uk>

> Perhaps it's not CPU that is blocking things, but I/O?  It should be
> visually
> and audibly obvious if this is the case -- the disk activity lights will be
> illuminated, and the HDDs will be making noises.
> If you can spare the RAM, consider setting up a tmpfs to hold your IVR
> prompts
> in memory.

The prompts are anyway cached in in memory by the disk cache so i don't
think it's the issue in this case. As stated above, i don't see much of
disk load on the NFS server as well.

On Mon, Mar 2, 2015 at 6:14 PM, Steve Edwards <asterisk.org at sedwards.com>

> You may be using a feature (i.e., meetme) that is single threaded. If you
> view the system using 'htop' instead of 'top' (or, press '1' while running
> top) you may see that a single CPU is maxed out while the others are
> relatively idle.

I did check the CPU load and it is distributed evenly between all the
cores. Most of the load is in "system", probably network handling in the

We do use ConfBridge a lot, but all conferences are on a single server and
the issue is on all the servers.

What other features are single-threaded?

Asterisk is almost the only thing that runs on the PBX servers. There are
also some PHP AGI scripts (5-10 per minute per server on average) and most
of the AGI functions are off-loaded to a java application on the central
server with fast AGI. But there is still a lot of dialplan logic that runs
on the PBX's. Maybe, huge dialplan is the key for the issue?

משיח NOW!
Moshiach is coming very soon, prepare yourself!
יחי אדוננו מורינו ורבינו מלך המשיח לעולם ועד!
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