I updated to VDSL (I use Zen) on Monday and now I can't get my Vodafone Sure Signal (VSS) to give me a data. I can make phone calls and send texts but no 3G data gets through.
Initially I used the BT Openreach supplied ECI modem plugged into the WAN2 port of my old 2830.
Now I'm using the 2850Vn without the ECI modem, but I still have the same problem. It's at F/W 3.6.3_2471201.

I've read lots of things to try but nothing has worked:
1) Port forwarding
2) Upping the MTU from 1492 to 1500 (using Telnet)
3) Disabling IPSEC on remote access control to allow the VSS (which uses IPSEC) to connect to vodafone systems
4) Accepting large incoming fragmented UDP or ICMP packets

I've also hard reset the VSS, and asked Vodafone to reset/resync the unit, but again nothing works.

I have a backup Sky ADSL line, which I've used before for the VSS but it was never reliable. It was always far more reliable on the Zen ADSL.

I know I can just use data through a wi-fi connection, which would be more efficient/faster etc, but the VSS is very convenient. I don't want to keep switching wi-fi on or off when ever I leave or return.

Some people say that VSS doesn't work with PPPoE period, others that it works fine, and others say that sometimes it works.

My phone is a Samsung Galaxy S2 with Jelly Bean 4.1.2 (international version). The APN settings are all fine, and 3G works fine away from the office.

It's almost working for me, but I'm out of ideas.

Hi MTCS,

I have heard of a similar issue a couple of months ago from a friend who also works in IT and my memory is patchy but this may help.

He found that the VSS was adding in extra data into the packets and by reducing the MTU he resolved the issue,it wasn't a massive reduction, but it resolved his issue, unfortunately he is no longer with Voda and cant remember any more than i can about the issue!

Hope this helps,

Best Regards,

Dave

Many thanks Dave,

I did a search and came up with a so called magic number of 1456, and possibly 1478. The page I found was at this link...
http://forum.pfsense.org/index.php?PHPSESSID=7156fec2ef76209b41fda14857cd1f07&topic=34387.15

It's very technical and way over my head, but it's worth a try, which I'll do tonight.

I had another thought which was maybe there is an MTU value for the LAN as well as the WAN, but when I telnet to the router there appears to be lan command. Ah well.
I'll see what happens tonight and update this thread.
I was thinking it might be worth isolating the VSS on a seperate vlan.

Cheers
Mike

Well the MTU values made no difference.

1456 prevented the router from getting online. It just wouldn't connect.
It's running with 1478 now, but still no 3G data through the VSS.

just tried an MTU of 1480, but still no 3g data.

I get a H symbol on my phone, same as before, but no apps can get data, only voice and text messages.

its the phone .. nothing to do with the VSS - i had the same problem.
I used another phone and 3g data worked (even though the original phone worked ok with it for a while).