# Xfinity On Demand GSM-2 error



## morac (Mar 14, 2003)

I don't know when this started since I haven't used Xfinity On Demand on either of my Roamios for over a month, but when I tried yesterday I got a GSM-2 error for locale code tivocrd-cmc-a5p.comcast.com. I kept trying and eventually I got in and I could play shows, but when. I existed and tried to get back in I got the error again. I'd estimate I get the error over 95% of the time I try.

I called Comcast and after getting bounced back and forth between their tech and cablecard department a few times (not a cablecard issue since when it works, I can play and use trick play) until I finally got someone who told me a GSM-2 error means my "guide data is bad", which is obviously not correct. The person told me he'd escalate the issue and call me back, but couldn't give me a ticket number since he'd need a supervisor to enter the issue into the system. I have a feeling he didn't do anything.

I went to the Comcast support forums and found others complaining about the same problem, but no one is having much luck with Comcast.

http://forums.xfinity.com/t5/Video-On-Demand/bd-p/CTV_OnDemand

Currently I managed to get in and am watching a movie on HBO On Demand, which I need to finish in one sitting because who knows if I'll be able to get back in again.

Any ideas who to contact about this?

By the way I originally started a thread in the help forums, but most people don't check that. 
http://tivocommunity.com/tivo-vb/showthread.php?t=535307


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## NorthAlabama (Apr 19, 2012)

just posted in the other thread (i have a premierexl):



NorthAlabama said:


> this is happening now in our market, too, same error:
> 
> (GSM-2) tivocrd-cmc-a5p.comcast.com​
> tivo support is tracking this issue, so please call if you see this comcast error, choose tech support, then cablecard issues, and add your box to the list.
> ...


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## tfratzke (Jul 11, 2003)

Same problem here in Minneapolis market. Just started this weekend. All Tivo's suffering from it. IF you repeatedly try to get in, it will eventually load. The one thing i did notice is when searching all sources to get a show the Comcast VOD does not show up as a choice, as i am guessing it can't search the service when it's not working correctly.


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## Mokeman (Dec 21, 2015)

tfratzke said:


> Same problem here in Minneapolis market. Just started this weekend. All Tivo's suffering from it. IF you repeatedly try to get in, it will eventually load. The one thing i did notice is when searching all sources to get a show the Comcast VOD does not show up as a choice, as i am guessing it can't search the service when it's not working correctly.


Are you saying that someone is saying that the "XFINITY On Demand" menu item doesn't appear on the right pane (under Netflix, and above "Hulu Plus") as shown here: ?










I've never seen that listed as a symptom to the GSM-2 error code. GSM-2 error is a "result" of selection XFINITY On Demand (aka "VOD" - Video On Demand). And it can't be either, since you can only get the GSM-2 error "by" selecting 'XFINITY On Demand'. Hence, no XFINITY On Demand menu item automatically means no GSM-2 error.

The GSM-2 error when selecting 'XFINITY On Demand' menu (shown highlighted above) looks like this:










I still have the issue today, but so far, I can still eventually get in by hammering on it with the procedure I outlined in my previous post. Today I was able to get in with only 3 retries. But I've seen it go as many as 20+ retries, but more typically 6-10 tries. You will eventually get it to work by retrying.

Q: Has Tivo many any official statements on this issue?


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## Mokeman (Dec 21, 2015)

morac said:


> By the way I originally started a thread in the help forums, but most people don't check that.
> http://tivocommunity.com/tivo-vb/showthread.php?t=535307


Yeah, - that's a good thread. Bottom line is that if you keep hammering on it (retrying), it will eventually work.

One question I have however (that I haven't seen anyone talk about here), is this: Is this happening with Comcast DVR cable boxes too, or is this just a Tivo-related issue ?


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## mayta_capac (Aug 9, 2009)

I have the same issue and error message. I am in the south jersey. I was able to get in after about 8 tries.


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## Mokeman (Dec 21, 2015)

mayta_capac said:


> I have the same issue and error message. I am in the south jersey. I was able to get in after about 8 tries.


Which Tivo device do you have - Romeo ?


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## morac (Mar 14, 2003)

Mokeman said:


> Q: Has Tivo many any official statements on this issue?


Nothing official, but when I called in, they were aware of the problem. Unfortunately it appears to be a problem on Comcast's side, so there's not much they can do other than work with Comcast to fix it.



Mokeman said:


> One question I have however (that I haven't seen anyone talk about here), is this: Is this happening with Comcast DVR cable boxes too, or is this just a Tivo-related issue ?


From what I've read On Demand on X1 was having issues earlier in the week, but those were resolved.

I've been having issues getting in touch with someone at Comcast who knows anything about the problem or who doesn't want me to jump through a lot of pointless troubleshooting steps such as re-entering cablecard info and the like, but I did manage to get a response on Twitter today saying that "...we have only been having issues with TiVo Roamio", which is as close to an acknowledgement of the problem as I've gotten.

The problem seems to be with Comcast's On Demand TiVo Internet Gateway which would explain why the problem is only affecting TiVo boxes.

There's a few threads on Comcast's support forums, though this one seems to be getting the most posts (requires logging in to read/post).


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## Mokeman (Dec 21, 2015)

Yeah, geeze, I just don't know....

I troubleshoot extremely complex 9-1-1 and VoIP systems for a living, and I have no clue on this one. Main issue is that I just don't know how VOD works, specifically how the Tivo Romeo does VOD, and/or how it interacts with any Comcast server, and whether or not it communicates over the Internet, or over the cable itself.

I took a packet capture during one of my "retry frenzies" trying to get VOD to work, and when it finally got in, and I'm just not seeing any network traffic to correlate it to. My Tivo Romeo is IP Address 10.0.1.3 :










Nothing gets sent "back" to the Tivo Romeo during this interaction, even when I finally get into VOD.

The conversation from the box to Comcast when selecting VOD isn't IP traffic, but rather some cable "upstream" channel dialogue.


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## Jay2tak (Jun 10, 2009)

Mokeman said:


> Yeah, - that's a good thread. Bottom line is that if you keep hammering on it (retrying), it will eventually work.
> 
> One question I have however (that I haven't seen anyone talk about here), is this: Is this happening with Comcast DVR cable boxes too, or is this just a Tivo-related issue ?


I have 2 Tivo's (Romino Pro & XL4) both had the GSM 2 error, so I tried my Comcast cable box (not a D V R) and it worked fine. I then tried my Tivo's and both worked fine??? Go figure.

Sent from my iPad using Tapatalk


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## morac (Mar 14, 2003)

Mokeman said:


> I took a packet capture during one of my "retry frenzies" trying to get VOD to work, and when it finally got in, and I'm just not seeing any network traffic to correlate it to. My Tivo Romeo is IP Address 10.0.1.3 :


I don't see any external connection attempts in your picture at all. Are you logging only LAN traffic?

For what it's worth, looking at my router logs I can see that my Roamio is connecting to tivovod-cmc-a-vip.sys.comcast.net (76.96.34.175) on TCP port 7287. I'm not actually looking at packet logs though. I would expect the traffic to be encrypted, so it probably wouldn't help if I did. Unless I see something as simple as a NACK or something. I will note, that's a public server so it's possible, though unlikely, that's it's suffering a denial of service attack or something.

Based on my understanding of how VOD works with TiVo, that server is the On Demand menu and control server. The TiVo connects to that server to grab the list of VOD programs and to control trick play during playback. All video comes in through the cable in coax and is decrypted by the cablecard.

In this case the failure is occurring connecting to the server, so it's happening before the cablecard even come into play.


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## morac (Mar 14, 2003)

I just tried 4 times and got in all 4 times, so it looks like it's working. 

Is it working for everyone else?


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## Mokeman (Dec 21, 2015)

Yup! - same thing here in the Seattle area (Covington Washington), - I just tried 4 times in a row, and got VOD to work first time.

Another unsolved mystery as to what was wrong, and what was done to fix it.

With all the people that work at Comcast (and Tivo), it amazes me that none of them are members here and post to forums like this.


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## Mokeman (Dec 21, 2015)

morac said:


> I don't see any external connection attempts in your picture at all. Are you logging only LAN traffic?
> 
> For what it's worth, looking at my router logs I can see that my Roamio is connecting to tivovod-cmc-a-vip.sys.comcast.net (76.96.34.175) on TCP port 7287. I'm not actually looking at packet logs though.


Where and how are you able to look at "router logs" ? Are you talking about your WiFi router ? What type, and where are the logs ?

The packet capture that I posted was a "WireShark" screenshot of a packet capture that I did with UNIX's 'tcpdump' on the network for everything going to/from the IP address of my Tivo Romeo. There is nothing coming "in" to my Romeo when I select VOD, so it's communicating via some cable "upstream" channel.

There is nothing customer-specific about the conversation between the TiVo and some Comcast/Tivo server (gateway?) for VOD that would requite it to be encrypted. Encryption (SSL) requires CPU resources, as does "decryption", so I wouldn't think that they would have designed it to be encrypted.

Also, Tivo apparently developed their own TCP protocol (TivoConnect) which WireShark is able to decode :










You can read about this protocol here.


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## morac (Mar 14, 2003)

Mokeman said:


> Where and how are you able to look at "router logs" ? Are you talking about your WiFi router ? What type, and where are the logs ?


It is a Wifi router running the third party firmware Tomato USB. All traffic that goes out to the Internet goes through it. I can see all TCP/IP connections (local ip address and remote server connected to) in realtime, but I can just see the ip addresses, not the packets.

There is no inbound connection when using Xfinity On Demand. The TiVo box makes an outbound connection to a Comcast server over the Internet.

Whatever machine you are running Wireshark on, it's not upstream from the TiVo box as the only traffic you are logging is broadcast traffic. You need to send all your network and Internet traffic through the box you are running Wireshark on.

Also the TiVo box can't communicate via an "upstream" cable channel as it doesn't have the hardware to do so. That's why it uses an Internet gateway Comcast set up.


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## Mokeman (Dec 21, 2015)

Yeah, - I guess I knew that the Tivo can't access the actual Comcast upstream channels (and thus the need for the Tivo gateways) - forgot about that.

As far as the packet capture, I forgot that I have the Tivo setup for WiFi.

I switched it to wired Ethernet to the switch, and re-captured the packet conversation in/out of the Tivo when selecting VOD. It starts out with a semi-lenthy HTTP conversation on port 80 (my Tivo is 10.0.1.6):










Notice how it starts a http connection to two different hosts at the same time (204.176.49.116 & 184.51.159.215).

Then after that conversation in completed and tore down (the FIN's), a huge data dump on port 7287 ensues :










Then it appears that the Tivo ends that dump by sending a TCP Reset (seen in red):










If you have WireShark, you can download my WireShark capture here and open it up in WireShark to look at it. 
I wish I would have taken a packet capture when this was all acting up. Oh well, - next time I guess.

Interestingly, some of those web URL's shown in the trace are the movie and genre icons (JPG's) that show up in the regular Tivo menu's before you ever select VOD.

Example (Muppets movie icon): http://i.tivo.com/images-production/collection/343/423/285343423/moviePoster_83x125.jpg


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## gkayakinbum (Dec 26, 2015)

I just now tried to access Xfinity VOD on at first one of my TIVO premiere's and the wife said look at this GSM-2 error. Then I tried it on mine upstairs and same thing. Just 3 weeks ago finally got both VOD working again then this. Uggh... I don't see anyone else posting so for everyone else I'm assuming it has been resolved?


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## slowbiscuit (Sep 19, 2006)

It's hit or miss again, keep trying until it works.


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