MTU on my 7800N is set as 1492 - don't think the router will allow you to set anything higher. However you should check what the optimum MTU for your connection is by following these simple steps:

1.Go to Start and select Run.

2.Type in cmd (Windows 2000/XP/Vista/7) or command (Windows 98/ME) into the Open: field. Hit the enter key or click OK. The DOS prompt should open.

3.At the DOS prompt, type in ping bbc.co.uk -f -l 1492 and hit the Enter key.

4.If you get the response "Packet needs to be fragmented but DF set", lower the size the packet in increments of +/-10 (e.g. 1472, 1462, 1440, 1400) until you have a packet size that does not fragment.

5.Now increase the packet size from this number in small increments until you find the largest size that does not fragment. Add 28 to that number (IP/ICMP headers) to get the optimal MTU setting. For example, if the largest packet size from ping tests is 1462, add 28 to 1462 to get a total of 1490 which is the optimal MTU setting and can be put in your router's settings!

In reply to a post by baby_frogmella:

In reply to a post by Banger:

Got the replacement today and its still stalling during 200mb downloads. Billion are looking in to it.

I presume you didn't go for the 7800N as you don't need wireless, however no 7800N reviewer (at least in UK)has mentioned this downloads stalling problem which you're experiencing because i'm sure many will also be connecting to broadcom gear at their dslam (even though the 7800N and 7800 are supposed to have the same Broadcom 6358 chipset). If the problem persists, It might be worth asking Billion support if you can directly send them the 7800 in return for a new/refurbished 7800N. Pretty sure you won't have any problems with the 7800N
PS
Billion support are normally very good so keep hassling them to get this sorted out ASAP.

I would prefer to sort out this one I have. Weird thing is if I set up multiple streams on a download eg DownthemAll on Firefox, no problem and can hammer my connection with max speed. One single download/stream and you get the 1 second pauses/TCP timeouts. Billion have escalated it to engineers. TBH it's pretty hard to spot unless you have a meter and monitor every download or video stream. Downloads are not a prob I have found a workaround but 3 mbit HD video streams maybe as it will cause pausing.

In reply to a post by Anonymous:

In reply to a post by prinknash:

In reply to a post by Banger:

Can someone with a Billion 7800 or N tell me what their router MTU is set to in the PPPoA profile. Mine was 1492 have changed to 1500 as the syslog was saying "unable to set mtu to 1500" a few times and stalls are less frequent.

MTU is set to 1492, which seems to be the default for PPPoA on my 7800N running firmware version 1.06e.

p

You could try 1478 or 1472 see which gives the best performance, your internal set up, wireless or Ethernet cable from router to pc ? what is the mtu set to on the pc? one sure way to find out if it's something related to the billion router or not is if you know someone with a different isp say be/02 or bt even and ask them if they wouldn't mind trying it on their connection, if it still does the same then it's related to the billion if not then it's your isp or the way in it's network is configured

PC MTU is 1492, tried a whole bunch of MTU settings on the Billion and it just seemed to adjust the time period at which the stalls happen which is pretty random and sometimes not at all just depends how the router is feeling.

Pinging [68.67.73.20] with 1500 bytes -> ..fragmented
Pinging [68.67.73.20] with 750 bytes ->bytes=750 time=130ms TTL=52
Pinging [68.67.73.20] with 1125 bytes ->bytes=1125 time=135ms TTL=52
Pinging [68.67.73.20] with 1312 bytes ->bytes=1312 time=138ms TTL=52
Pinging [68.67.73.20] with 1406 bytes ->bytes=1406 time=137ms TTL=52
Pinging [68.67.73.20] with 1453 bytes ->bytes=1453 time=138ms TTL=52
Pinging [68.67.73.20] with 1476 bytes -> ..fragmented
Pinging [68.67.73.20] with 1464 bytes ->bytes=1464 time=138ms TTL=52
Pinging [68.67.73.20] with 1470 bytes ->bytes=1470 time=138ms TTL=52
Pinging [68.67.73.20] with 1473 bytes -> ..fragmented
Pinging [68.67.73.20] with 1471 bytes ->bytes=1471 time=139ms TTL=52
Pinging [68.67.73.20] with 1472 bytes ->bytes=1472 time=138ms TTL=52
The largest possible non-fragmented packet is 1472 (1500 - 28 ICMP & IP headers).
You can set your MTU to 1500

I used TCP Optimizer from Speedguid,net which does the hard work for you. Gonna try some different window sizes see if that makes any difference.

Edited by Banger (Wed 21-Dec-11 08:50:27)

1.06f is out tomorrow. Billion are going to send it to me to try.

In reply to a post by Banger:

1.06f is out tomorrow. Billion are going to send it to me to try.

Cool, let us know how you find 1.06f. Might even try it myself

1.06f has been delayed due to bugs. One good thing my line has been up 7 days without a drop at 2db SNR despite the throughput probs which seem fairly random now.

I have a new problem it reboots after so many days uptime. :|

Finally got a reply from Billion engineers on the download pauses.

"Dear UK,



If user download such a big files, Router will temporarily pause the network and will do regularly defragmented refresh on system memory inside to avoid Interruption occurs.

This does not affect to the files download failed for your further information. "

So looks like a memory problem, have asked when this will be fixed.

*Update*

No further help from Billion presume they are still looking at it but they did say they cant repeat it in the Lab.

I'm beginning to wonder if it is the linecard or MSAN. I can hammer downloads with multiple streams eg 4 and no pauses occur on say a 500 mb download file. Would of thought if it was the router it would still pause no matter how many streams. It's a puzzle. Max speed is 2.0 mb/s but with pauses, if there are a lot of them speed can drop to 1.5 mb/s. Multiple streams and it averages at 2.0 mb/s.