Comcast, Dropped calls, Lag, timeouts, UDP

Posts: 34 · Vonage Forum Junior Joined: Jun 20, 2006 Posts: 34

If you are having a problem with Comcast please post your modem information, location and symptoms.

Posts: 1 · New Forum Member Joined: Jul 04, 2006 Posts: 1

Location - Douglasville, GA
Modem - Motorola 5100 series
dropped calls, poor quality, unreliable vonage service
ISP - Comcast Extreme (8mb/768k)

Posts: 6 · New Forum Member Joined: Apr 25, 2003 Posts: 6

Everett, WA
8 meg down 768 upload
dlink dcm 202

no boyd can hear me after a all has been concected for agout 5 to 10 secs constanttle propping out the listener hears echoing and then nothing

Web Cam freezing and dropping out on yahoo, msn, skype,

slow download speeds havnet sceen the power boost havnet sceen 8 meg yet nor 6 meg cloest i have had was 5.5 megs all stats via myvitalagent

Posts: 1 · New Forum Member Joined: Jun 26, 2006 Posts: 1

Springfield, MO

Dropped calls and bad audio today since about 3 pm central time.

Posts: 34 · Vonage Forum Junior Joined: Jun 20, 2006 Posts: 34

For those of you who are entering your information, I did forget to include a request for your revision numbers on your modems and firmware revision if you can locate it. For those of you who might be looking for a solution to your problem, I was successful for a few months with an old SB3100. You may also want to try a SB4100, make sure however that it is DOCSIS 1.1 compatible or you might sacrifice speed. I have recently moved to a DOCSIS 2.0 modem that is a Linksys modem model #BEFCMU10, you can purchase it online at stores like newegg.com, amazon.com, etc. at a discounted price.

I would also like to add that some of you, who have not tried it should try pingplotter to find which router hop you are having difficulty with and make sure that you have contacted your ISP to ensure the power levels to your home. When I first started on of several problems was that my ISP had placed a shunt on my line because the previous owners had used the wrong splitters and had unterminated cable lines.

FYI, unterminated cable lines will decrease your power level and decrease your connection speed to your ISP.

Posts: 31 · Vonage Forum Junior Joined: Jun 11, 2006 Posts: 31

SB5120 modem, Docsys 1.1, 2.0
Vonage - motorola adapter
Comcast

Problems since April.

Symptoms:
VOIP - I can here them but I drop out for 10 to 20 seconds at a time frequently throughout the call. Occasionally choppy. Problems occur every single call that I must make an immediate announcement for them to stay with me, I will drop out - be able to hear them, they just won't be able to hear me for spells.
Can not video conference anymore, broken audio, video freezes (vrmeetings/meetingplaza w smart bandwidth compression that even a dial up should fly and MSN). We do not do gaming.

Upload issue now showing on simply surfing net as usual, data has to be transmitted several times to go.

DX:
Ping tests and tracerts - heaps of time outs, packet loss, latency 100 - 300 ms
VOIP tests - 59% - 82% QOS usually
Speed tests - sometimes good, sometimes under 300 on my UL.
Modem log - warnings, criticals, time outs - box loses signal.
Have taken Vonage adapter out of loop - no difference.
Have taken network down and run one pc through SB5120 - no difference.
Found hundreds of uers on this and broadband forums all with same complaint on SB5120: VOIP UL issues, VPN, gaming, video conferencing problems.

Comcast response:
A unique and mysterious issue.
Phone support sees modem dropping out hundreds of times but techs to house say they don't know what they're talking about.
Replaced line pole to house.
Made me swap modem out at local Comcast store (replaced with same model - SB5120).
Complete denial of any issues whatsoever.
Mad at Fred who posted the Comcast engineers name and number who admitted via his own bench-testing that there WAS a problem with the 5120.

Best guess:
Firmware issue with SB51xx's - when we first plugged the new one in we were screaming and functional again - within a matter of hours (firmware updates) we were dead in the water again.

Solution:
Waiting for my new Linksys modem to arrive, it has solved Fred and many others problems immediately.

Best wishes to all just starting out on this road, I've been at battle since April.

Gina
12 miles south of Boston

Posts: 49 · Full Forum Member Joined: Nov 27, 2004 Posts: 49

I moved within my same neighborhood June 1. Kept Comcast service, SB5120 modem, and Linksys RTP 300 Vonage adapter.

From April through May I had the periodic loss of callers being able to hear me. Once I moved the problem never happened again.

The only difference is that I'm on a different Comcast neighborhood node and my modem was "reset" by Comcast.

Posts: 31 · Vonage Forum Junior Joined: Jun 11, 2006 Posts: 31

Hey PDrayton - hope it stays good - they no doubt rolled you back but if you cop a firmware update (they say motorola dishes those) you may be back to square one. I'm told they can flag you to leave you alone on those but don't nkow as I believe that or not. When we first swapped out our modem (another SB5120) it was good for all but 2 hours. See my previous post above for the headache history.

Posts: 20

West Saint Paul, MN (55118)
651 area code
Comcast HSI (currently 8Mbs/784Kbps)
Motorolla SB5100 Surfboard cable modem
VTech 8100 IP router

Some dropped calls. Some echo. Just this month, the voice of the person we are talking to cuts in and out intermittently. They can usually hear us the entire time.

Speed test statistics
---------------------
Download speed: 9358840 bps
Upload speed: 738288 bps
Quality of service: 47 %
Download test type: socket
Upload test type: socket
Maximum download pause: 50 ms
Average download pause: 2 ms
Minimum round trip time to server: 39 ms
Average round trip time to server: 40 ms

VoIP test statistics
--------------------
Jitter: you --> server: 6.7 ms
Jitter: server --> you: 8.1 ms
Packet loss: you --> server: 0.0 %
Packet loss: server --> you: 0.0 %
Packet discards: 0.0 %
Packets out of order: 0.0 %
Number of supported VoIP lines: 12
Estimated MOS score: 3.9

Posts: 34 · Vonage Forum Junior Joined: Jun 20, 2006 Posts: 34

I would suggest as part of the first step in troubleshooting your problems, using a program like PingPlotter to plot your router information and statistics. This should help you with tech support, if you are noticing a large number of packets lost at your modem and at one of the routers then it is a communication error between your modem and the router, multiple problems could exist, first you should have your isp verify that your line to the house is good and that you do not have any unterminated "outlets"/"jacks" in the house if you are using cable modem. This can lead to signal degredation, also verify that you have good splitters in/outside the house where you have service, the more splits the less the quality of the signal. I digress, if you see 100% packet loss in pingplotter that simply means that the specific router does not accept ping requests, do not be alarmed you are still able to use these statistics. Do not let your ISP confuse you, they will say the reason for lost packets is because of priortization, BS!! Packet loss is packet loss!! If you have verified that your line to the house is good and the isp tells you that they don't support vonage or other services outside their control, BS!! They are correct they don't support vonage, but they certainly darn well should be providing reliable UDP service as well as TCP service, if the customer service rep doesn't know what these mean then ask for a supervisor or the next tier technician, they aren't likely to be able to help you at this point. As a last resort you should change out your modem, don't get me wrong, you can do this first but you might be shelling out $40 - $50 for a new modem. Make sure that wherever you buy your new modem, different model than a SB51xx, that you can return the opened package if it does not solve your problem! Please feel free to post any questions on this discussion, I wish to help spread the word. Smile