Occasional "hashing" of incoming audio on GV calls

[chetstone]

Most of the time my GV calls are very clear but occasionally the incoming voice is garbled as if it were run through a shredder. This is always associated with a spike in IP traffic between the OBI 110 and some sites in Googleland. These spikes seem to be sporadic HTTPS/SSL/TCP interspersed in the normal UDP stream (as seen in Wireshark). The spikes happen every minute or two but only occasionally are they severe enough to cause the interference in the audio.  Looking at the IP traffic monitor in my router, the spikes at their worst appear to double the bandwidth normally being used in the call. Which is not that much, maybe 200Kb, certainly not enough to cause a blip in my clean 8Mb ISP feed, but the Obi itself doesn't seem to able to handle the traffic.

I don't know what the conversation is between the OBI and google, but they seem to be about certificates and some such. Don't know why they would be necessary in the middle of a voice call.
I could post the wireshark dump of these conversations if anyone is interested.

Has anyone else seen this? More importantly, can anything be done about it?

thanks.

[pc44]

Hi chetstone,

That is interesting.  Is there any time pattern to the spikes in traffic that you are seeing?  For example, do they occur in consistent time intervals (i.e. every 10 seconds or 60 seconds)?

Sounds like some sort of authentication or 'register' cycle.  If you have the data to post, it would be interesting to see.

pc44

[chetstone]

Hi chetstone,

That is interesting.  Is there any time pattern to the spikes in traffic that you are seeing?  For example, do they occur in consistent time intervals (i.e. every 10 seconds or 60 seconds)?

Sounds like some sort of authentication or 'register' cycle.  If you have the data to post, it would be interesting to see.

pc44

The regular spikes are much less than I saw the last time I was looking at this a couple of months ago.. at that time they seemed to be occuring semi-regularly at about 2 minutes +/- 30 seconds. Now all I see is a very short Jabber/XML exchange every 60 seconds.

I have posted the wireshark dump at https://dl.dropbox.com/u/584383/Obitalk_topic_3421.pdf. You can see this exchange every minute for the first 10 minutes of the call. Then, on page 4 at 605 seconds, the intense conversation started. I noticed the interference in the audio at 608 seconds. The interference continued for about 10 seconds.

[pc44]

chetstone,

Thanks for posting that.  It was certainly interesting to see.  I do see the increased activity you noted, and it does seem like some sort of secure-handshaking / certificate-exchange between the OBI and GV.  Not sure what it is but certainly amusing.  Perhaps with time, someone will determine exactly what is occurring and what can be done to resolve the traffic issues invoked by it.

pc44

[chetstone]

Most of the time my GV calls are very clear but occasionally the incoming voice is garbled as if it were run through a shredder. This is always associated with a spike in IP traffic between the OBI 110 and some sites in Googleland. These spikes seem to be sporadic HTTPS/SSL/TCP interspersed in the normal UDP stream (as seen in Wireshark). The spikes happen every minute or two but only occasionally are they severe enough to cause the interference in the audio.  Looking at the IP traffic monitor in my router, the spikes at their worst appear to double the bandwidth normally being used in the call. Which is not that much, maybe 200Kb, certainly not enough to cause a blip in my clean 8Mb ISP feed, but the Obi itself doesn't seem to able to handle the traffic.

I don't know what the conversation is between the OBI and google, but they seem to be about certificates and some such. Don't know why they would be necessary in the middle of a voice call.
I could post the wireshark dump of these conversations if anyone is interested.

Has anyone else seen this? More importantly, can anything be done about it?

thanks.

I'm still surprised that no one else is complaining about this but if you have this problem (and IMHO everyone should have it, because it seems to be a design deficiency in the OBI 110) there are two workarounds.

It appears that the conversation involving certificates revolves around voicemail notification, so turning off Google Voicemail Notification in your Obitalk Configuration is the simplest and most certain fix. This exchange occurs once an hour (if there are no messages --- probably more often when there are messages) and hashes the voice conversation in both directions for 5-20 seconds. Turning it off stops it completely.

The other fix, which I tried before stumbling on the voicemail notification thing, is to turn on QoS in your router. Setting Obi UDP traffic to the highest priortiy, Obi TCP traffic to the lowest, and everything else to normal priority, I only experienced the hashing noise once or twice in two weeks of light calling.

Turning off voicemail notification is the best fix for me, because it was annoying me anyway. Probably due to an idiosyncracy in the phone I was using, often, when I would go to answer a call, the phone would not allow me to answer until I first pressed "End" to cancel a "Message Notification off" message. And I get notified right away when there's a message anyway --- either by my Google Voice iphone app, or it comes in my email.