SIP - IAX - SIP call problem

Hi,

Hope someone can help me on my asterisk problem.

I have 3 asterisk server located on different locations.

only one has the zaptel card to call outside.

sip to sip calls and outside calls are working perfectly.

But calling from one asterisk to another via IAX is very bad.
what i mean is th voice quality is very choopy. what i do for me to call someone in my other office is for me to dial our external number/ trunk line then dial it’s extension. That way voice quality is good.

What i don’t understand is why calling directly from one asterisk to another via IAX is very bad.

Hope someone can help me.

Thanks
: )

what is you iax config look like.
(iax.conf)

Then I can take a look at it.

Are you doing any qos on your routers for sip but not iax ports

IAX2 port is 4569. IAX port is 5036.

[general]
bindport=4569
bandwidth=medium
allow=all
disallow=lpc10
allow=gsm
jitterbuffer=no
maxexcessbuffer=750
dropcount=2
tos=lowdelay

yes i have QoS on my routers. But i 'am not aware if it is for SIP or IAX. How can i tell?

what kind or router is it.

Cisco:
the command show run on it will show you the running config.
cisco.com/en/US/technologies … Paper.html

Juniper
kb.juniper.net/CUSTOMERSERVICE/i … c3c1901ac4

what protocol are you actually wanting to run between sites?
ulaw?
gsm?

and you might want to glance at you sip.conf and see what protocol it is using.

This is what my sip looks like:

SIP.conf

[general]
context=default
port=5060
bindaddr=0.0.0.0
srvlookup=yes
tos=lowdelay
videosupport=yes
disallow=all
allow=ulaw
allow=gsm
allow=h263

IAX.conf

[general]
bindport=4569
bandwidth=medium
allow=all
disallow=lpc10
allow=gsm
jitterbuffer=no
maxexcessbuffer=750
dropcount=2
tos=lowdelay

i noticed that port in SIP and bindport in IAX is different. which should i follow? should i changed it?

add

allow=ulaw

to your iax.conf on both sides it looks like you are using ulaw as the codec on sip.

GSM is a much lighter weight protocol but not very high sound quality.

You might want to look this over it will explain codecs better
voip-info.org/wiki-Asterisk+codecs

After you make this change you will need to reload your config but then you will be good try that out and let me know what you find.

Thanks

thanks a lot for the help and info.

i’ll test this and will surely give feedback.

Hi, test new config after adding allow=ulaw on my iax and still have bad voice quality. Not as bad as before but still chopy.

what kind of router do you use; sounds like we need to enable some qos on iax port.

i’am using cisco ASA5510 firewalls. one for each sites.