Frequent "hickups"

HSPA setup and configuration (for wireless networking, please use the 'Networking issue' forum)
camh
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Joined: Mon Jan 03, 2005 3:07 pm

Re: Frequent "hickups"

Post by camh » Fri Jun 19, 2009 2:12 pm

JasonM wrote:When the issue happens, the computer doesn't indicate it is losing contact with the modem for example?
No. When the stalls occur, I can continue to get status from the modem, indicating that the modem is still functioning and that the computer can still communicate with it. There is nothing in the system log indicating a loss of contact with the modem, as there is when I unplug it.

I have run tcpdump on the other end of the pings and it appears that the delay is in sending packets, not receiving them. That is, at the remote end, I notice the stall too.
Testing with a supported operating system might reveal the same results, and if so - we can then escalate to our supplier.
That's a shame. I can't justify buying a copy of windows just so I can provide the same info. Is there something else I can do?

JasonM

Re: Frequent "hickups"

Post by JasonM » Fri Jun 19, 2009 2:23 pm

If it happens often enough, you might be able to test on a friend or neighbours computer?

Without isolating the unsupported operating system, it'll be difficult to determine if it's an error in the drivers / software you are using, and that of the software supplied on the device.

The software shows registration to the network (i.e. "YES OPTUS").
Add to that, the ability to force the modem to WCDMA / HSDPA only, to remove the possibility of the device changing between modes.
And to force the network mode to GSM900/1800/WCDMA 2100.

Does the service perform OK with regard to speeds (so it's not a congestion issue)?

camh
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Joined: Mon Jan 03, 2005 3:07 pm

Re: Frequent "hickups"

Post by camh » Fri Jun 19, 2009 4:24 pm

There's a non-locked-down windows laptop here at work that I've found, but I wont be able to do any tests until Monday. I'll let you know the results then.

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Dazzled
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Re: Frequent "hickups"

Post by Dazzled » Fri Jun 19, 2009 8:45 pm

camh, I've just been looking again at e169-stats.c available at http://www.mavetju.org/download/ (I referred to it earlier). The programmer, Edwin Groothuis, is from Sydney, and he has cracked part of the e169 modem output. You will have to change the open statement and modify the curses output. He doesn't unwrap SRVST and BOOT, but it looks like he found the delay info.

I read through the Huawei forums on this a while ago, and they will run the length of the Great Wall in their undies before they give a simple direct answer to firmware output questions. There is a group working on reading these, so it should be available in Gnome applets reasonably soon.

camh
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Joined: Mon Jan 03, 2005 3:07 pm

Re: Frequent "hickups"

Post by camh » Sat Jun 20, 2009 12:27 am

I can't see anything new in that e169-stats.c source. It parses a SRVST line and displays its value, but I have no idea what it means, nor have I seen a SRVST line in the output of /dev/ttyUSB2. It also calculates the RSSI value as a dBm value, but that doesn't mean much to me either. The only delay calculation seems to be based on not receiving any data on /dev/ttyUSB2 (/dev/cuaU0.2 - old school unix dev name).

Otherwise, the parsing of DSFLOWRPT seems to stop at the same point as the other program, and displays "Green" if the modem falls back to GPRS mode.

camh
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Joined: Mon Jan 03, 2005 3:07 pm

Re: Frequent "hickups"

Post by camh » Thu Aug 27, 2009 3:39 pm

JasonM wrote:Testing with a supported operating system might reveal the same results, and if so - we can then escalate to our supplier.
When I first posted this thread, I mentioned in the end I had found a Windows laptop to try this out on a supported OS. After I got everything installed, the problem went away, on both the Linux host and the Windows host.

The problem has started again. I am seeing stalls of between 4 and 10 seconds, 5 times a minute, based on ping output. Sometimes the ping packets are just delayed, so I see a round-trip time of between 4 to 10 seconds, other times, I just get no response (packet loss). I have just had a 50 second and a 37 second stall as I write this message. This impacts my interactive ssh sessions, web browsing and VoIP.

I am also having multiple drop-outs each day, when the PPP session drops and needs to be re-established. Sometimes it takes a while (a few minutes) to re-establish, other times it re-establishes instantly.

When the stalls occur, the modem drops back to WCDMA from HSDPA. I have full signal strength (5 bars), and connected to the "YES OPTUS" network. I am situated in South Melbourne. The HSPA modem (E169) is stationary all day. I do not believe that this is caused by loss of signal. I have the Wireless Broadband application set to "WCDMA only" so it should not be falling back to GPRS.

I am currently stalled for over 5 minutes. It has not disconnected - the light is not flashing - it is solid dark blue.

I have been having these problems for the last week or so. Prior to that for the last couple of months I have had no problems. Currently the service is too poor to use effectively.

Would you please escalate this to your supplier? Or is there some other tests I need to do?

camh
Posts: 74
Joined: Mon Jan 03, 2005 3:07 pm

Re: Frequent "hickups"

Post by camh » Thu Aug 27, 2009 4:10 pm

camh wrote:Or is there some other tests I need to do?
Actually, since I've done the testing as requested earlier in this thread, I've opened a ticket for this issue.

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