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rblizz

join:2001-12-16
North Richland Hills, TX
Reviews:
·Callcentric

[General] Crackling on PSTN calls

I helped set my nephew up with a CallCentric account using an SPA1001 we had on hand. I didn't know how well it would work because he uses a wireless, radio wave Internet service. (He lives in the country.)

At any rate, CallCentric to CallCentric calls work fine, but anything handed off to the PSTN network is iffy -- the CallCentric incoming side is fine but the outgoing randomly "crackles." I was able to verify it by calling my nephew from my cell phone. He said his side was fine, but I heard bursts of "crackling" almost like electronic cross-talk. It would stop for a while, then come back -- a lot like a conversation.

The SPA1001 was tested before we handed it off to him and it worked fine to PSTN calls from here (using his new CallCentric account) so I'm guessing it's an issue with his local ISP.

Does anyone have any idea what would cause something like this? I set his codec to G711 -- could it possibly help to set it to G729?

I know it's an odd problem. Just curious if anyone has ever dealt with anything like this.



Don Dulac

@optonline.net

said by rblizz:

I didn't know how well it would work because he uses a wireless, radio wave Internet service. (He lives in the country.)

(snip)

I set his codec to G711 -- could it possibly help to set it to G729?

G711 codec is great if there is optimal bandwidth, and a stable connection with low jitter.

For his situation, it certainly pays to try the G729 codec. It is logical to do so, and easy to implement as you know.

Ken1943

join:2001-12-30
Denver, CO
reply to rblizz

I just had that happen, for a short time, on two calls about an hour & half ago. That would be 2:30 pm Mountain time. Only for about 2 minutes on each call.


ImpetusEra
Premium
join:2004-05-19
00000
reply to rblizz

»www.cisco.com/en/US/tech/tk652/t···e4.shtml

Maybe some useful general information there to resolving the issue. Could also try adjusting RX and TX gain values.


rblizz

join:2001-12-16
North Richland Hills, TX
Reviews:
·Callcentric
reply to Don Dulac

said by Don Dulac :

G711 codec is great if there is optimal bandwidth, and a stable connection with low jitter.

For his situation, it certainly pays to try the G729 codec. It is logical to do so, and easy to implement as you know.

Okay, I'll try it. Thanks. Didn't think about jitter. I've had so little trouble that I've never had to really tweak much.

rblizz

join:2001-12-16
North Richland Hills, TX
Reviews:
·Callcentric

1 edit
reply to ImpetusEra

said by user=Ken1943 :

I just had that happen, for a short time, on two calls about an hour & half ago. That would be 2:30 pm Mountain time. Only for about 2 minutes on each call.

I wonder if this is part of whatever is going on with the Internet the last few days. I've had a lot of weird delays on various sites, while others are working fine. Not a local issue, I don't think. Phone has been fine here, throughout.

Edit: This was supposed to be a response to Ken1943. I originally quoted the wrong message when responding.

rblizz

join:2001-12-16
North Richland Hills, TX
Reviews:
·Callcentric
reply to ImpetusEra

said by ImpetusEra:

»www.cisco.com/en/US/tech/tk652/t···e4.shtml

Maybe some useful general information there to resolving the issue. Could also try adjusting RX and TX gain values.

Thank you very much for the link. It's bookmarked and I'm going to study it now.

rblizz

join:2001-12-16
North Richland Hills, TX
Reviews:
·Callcentric

1 edit
reply to rblizz

UPDATE -- I had my nephew switch to the G729a codec and it appears to be working better (hardly any pops). But it still seems a bit "iffy" to me (maybe just the difference in G711 and G729) -- though it was hard to tell as my Internet connection was iffy -- and my cell phone is never good at home -- Sprint tower is on the wrong side of the power lines.

I asked my nephew for his router model. If I remember right, it's a D-Link DIR-615 which, apparently, had trouble when set to the default SIP ALG firewall setting. I don't (yet) know which firmware version he has. We'll talk some more tomorrow.

If anyone knows anything about setting up a D-Link DIR-615 for VoIP (there seems to be some conflicting instructions) I would appreciate any pointers. The router is definitely not a deal killer -- if he needs to get rid of it and buy something else, he'll be glad to do it. I'm also wondering if we can't plug the SPA1001 in front of the router -- not sure what kind of modem he's plugged into. Might need to add a switch.

Thanks for any pointers.