Internet stops working after 30 seconds.

ATIorNvidia · 31 May 2009 at 15:35

I've recently started to have problems with my Internet, everytime I reset my Modem, the Internet works fine for about 30 seconds to a minute, then it just hangs, I see no disconnection prompt or anything, everytime is fine in the status page including the IP address.

Now I phoned up my ISP (Virgin Media) and explained my problem to them, and they told me it was a faulty Modem, and that they'd send a new one out to me. I just received my new Modem today, connected it up and registered it with Virgin, but I'm still having the exact same problem as I had with my old Modem, so what could be the problem?

JimAroo · 31 May 2009 at 16:11

I would head over the the VM newgroup.

virginmedia.support.broadband.cable

Excellent support in there.

pennywise · 31 May 2009 at 16:45

JimAroo said:
I would head over the the VM newgroup.

virginmedia.support.broadband.cable

Excellent support in there.

Bit pointless considering his "internet" hangs after 30 seconds.

Is it only on one computer or do you have others you can check?

tolien · 31 May 2009 at 18:08

Do you have a router or anything attached to the modem?

JimAroo · 31 May 2009 at 21:42

pennywise said:
Bit pointless considering his "internet" hangs after 30 seconds.

Is it only on one computer or do you have others you can check?

The tech support guys can check his line/modem and his part of the network. Generally picking up a fault.

Rroff · 31 May 2009 at 23:03

Have you tweaked the MTU recently?

see what this says if you can run it long enough to check http://www.speedguide.net/analyzer.php

ATIorNvidia · 2 Jun 2009 at 12:39

I've noticed something, it seems to start happening everyday at around the same time (between about 12PM and 2 PM) and it starts working flawlessly after about an hour or two. It's been like this for the past 4/5 days or so. If it was a problem with Virgin Media why would they of diagnosed my problem as a faulty modem and send me a new one?

Anyway, speedguide.net is giving me this:

TCP options string = 0204057001010402
MTU = 1432
MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput. If you are using a router, it could be limiting your MTU regardless of Registry settings.
MSS = 1392
MSS is not optimized for broadband. Consider increasing your MTU value.
Default TCP Receive Window (RWIN) = 65535
RWIN Scaling (RFC1323) = 0 bits
Unscaled TCP Receive Window = 65535

Note: TCP 1323 Options need to be enabled for RWIN over 2^16 (65535).
For optimum performance, consider changing RWIN to a multiple of MSS.
Other RWIN values that might work well with your current MTU/MSS:
64032 (up to 2 Mbit lines, depending on latency. MSS * 46)
128064 (1-5 Mbit lines, depending on latency. MSS * 46 * 2)
256128 (2-14 Mbit lines, depending on latency. MSS * 46 * 2^2)
512256 (8-30 Mbit lines, depending on latency. MSS * 46 * 2^3)
1024512 (25-60 Mbit lines depending on latency. MSS * 46 * 2^4)
bandwidth * delay product (Note this is not a speed test):

Your TCP Window limits you to: 2621 kbps (328 KBytes/s) @ 200ms
Your TCP Window limits you to: 1049 kbps (131 KBytes/s) @ 500ms
MTU Discovery (RFC1191) = OFF
Time to live left = 112 hops
TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 00000000 (0)

Edit: I am using a router, but I have tried it on another PC and on a Laptop.

Edit 2: Just phoned VM again and they told me its a problem in my area, and they only discovered it yesterday, so problem solved I think.

About the MTU thing though, is there something else wrong there?

Hyper · 2 Jun 2009 at 12:55

Sounds like a virus to me,

Once your internet "goes off" can you still ping websites via cmd?