Good old insufficient bandwidth

Question

i am going mad trying to figure out how to troubleshoot my "insufficient bandwidth to maintain the conference" problem. i have just moved from one side of north america to another, and i can no longer video chat with anyone using ichat, nor can i audio chat.
i have been reading the forums and trying the different fixes, but it seems that the problem is slippery one with no one solution. here is my particular setup, and what i have tried:
-powerbook g4 running 10.4.3
-ichat av 3.1
-isight
-aliant dsl service with 1.5 mbps download (i've checked using dlsreports speed tests, and i get 1157 kbps down/339 kbps up)
-comtrend ct-301 adsl modem (which is NOT configurable, according to my service provider)
-airport express base station with airtunes as my wireless
i've never had a problem using ichat until now, and only in this location. i know that the problem is specific to my isp, because i can use ichat audio/video just fine at work, in my old apartment (where i had cable internet), and at a friend's house (with dsl).
-i have tried every streaming speed in quicktime.
-my ichat bandwidth limit is set to none
-i've tried changing the login port in ichat from 5190 to 443
-i've tried plugging in directly to my dsl modem, rather than using airport
-i have firewall off
-my service provider tells me that they have custom built-modems that cannot be configured
-i'm reading the forums for any clue
-i cannot switch service providers, because cable internet is not supported in my building. besides, my property managers have a contract with aliant, such that only they can provide internet to my building
what else can i try?
thank you in advance for any help i can get.
powerbook g4 Mac OS X (10.4.3)

Answer 1

Hi,
This is the first time I have posted to the forum, although I find myself looking for solutions here quite often.
I am experiencing the same problem as the inital post, and use the same ISP, the same modem, as well as airport express. I have tried all the same solutions mentioned (disable firewall, plug-in directly to modem etc.) with no change in results.
- I have an imac intel running 10.4.5 with ichat 3.1.2 and built in isight
- speed test results were 831kbps download and 272 kbps upload
I tried downloading IPNetMonitor X and scaned the ports as was suggested by Ralph Jones using the IP address of a buddy and received results which said no ports were blocked. I also successfully pinged the same buddy's IP address as suggested.
Here is the weird twist: I have tested ichat with this same computer at my workplace. We use the same ISP, with airport extreme, and it worked perfectly on the first try. The only difference (apart from the modem model number) is the fact that our account at work is called "highspeed" whereas at home I have the upgraded service called "ultra highspeed". When I upgraded to ultra, I did not receive a new modem- all I had to do was change my user name setting and reset my modem.
To further test my theory, I tried the ichat test again from two other locations, one using high speed and one using ultra, with the exact same results.
While I had my father's computer, identical to mine, here at home, I was able to video chat and audio chat between the computers without using Bonjour.
After a lengthy and frustrating discusssion with my ISP, they have told me that there is no difference with both services other than improved speeds, and that the problem is on my side of the modem, not theirs. I suggested that they send me a different brand of modem, but they don't seem to think it will make a difference.
I am hoping that this new information might provide a clue, or that other users might be able to offer more suggestions I could try. I'd love to have specific questions to ask my ISP, with hopes that it might lead them to explore the right avenues to help me solve this problem.
Thanks for any help!