Can a 10/100 switch cause jitter/bad audio


#1

Hi,

I am in the process of installing * in my office.

Currently we are making use of snom 190 sip phones (very nice BTW), we are experiencing very bad audio on internal and outgoing calls (almost as though the audio between the calls are being clipped).

When the switch is removed and the phone is connected directly to the asterisk box, out going and incoming calls are crystal clear.

The switch is an 10/100 LG 8 port unmanaged cheap palm sized switch.

Can anyone tell me if the switch is the problem before I go and invest in an expensive switch. If so which switch should one consider?

Sorry for the lame question but we are at our wits end.

We have played with the jitter settings on * with little or no significant improvements.

I will appreciate any help.

Thanks.


#2

Currently there are no jitter buffer settings for sip in asterisk. (although there are some patches to do that).

The switch could cause that, from my experience most cheap switches will handle it just fine, as long as you dont overload them with other traffic of course.

If you want an expensive one, buy some cisco managed switch.


#3

Thanks,

Replaced the switch and the problem was solved (weird thing is that the switches were all brand new).

Beware of the cheap stuff.


#4

I don’t think you need to use a higher end managed or unmanaged switch. As long as you are running Cat5e and 100Mb/s everywhere all you need is a decent unmanaged switch. By decent I DO NOT mean Dlink or Netgear, garden variety Linksys and presumably not LG. I didn’t even know LG made switches.

I would pay maybe a $100 more for something that has a better quality power supply, connectors, and decent autoprotection against broadcast storms. That should include any mid range unmanaged switch. I think the “business grade” Linksys stuff would fall into this category(NOT the Linksys stuff you find in consumer stores). Zyxel stuff is definitely mid grade. There are lots out there but NOT anything you will find in Best Buy or anything like that. Look on professional business phone system company websites and look at what they are selling.