Hello All,

This is a bug, I've had it tested and fixed. The MTU does not actually change just let's you think it has in the advanced set-up page on certain browsers.

In the next release of firmware, we have changed PPPoA to allow 1500 and PPPoE will stay at 1492 as per standards.

Regards

Sounds good

In reply to a post by UKDoc:

The MTU does not actually change just let's you think it has in the advanced set-up page on certain browsers.

But hasn't anyone with the newer BrightBox actually tested it with Working out your maximum MTU that it reports no fragmentation of packets?

when should we expect the new firmware?

cheers

Afternoon XRaySpeX

I have just tried that link "Working out your maximum MTU".

It reported Fragmentation at the standard setting.

I then tried-
1400 - NO Fragments
1450 - NO fragments
1460 - No fragments

1470 - NO REPLY
1465 - No Reply
1462 - No fragments

1464 - Highest value with both "No fragments" and with "Ping Replies".

So I have left the MTU at 1464.

-------------------------------------------------

My first impressions are-

No obvious variation on any of the Speed Tests-
TBB standard
TBB Flash
BT Beta

However the loading of pages does seem slightly faster.

Nothing else was changed.

I'm a bit confused by your numbers. Are they Ping Packet sizes or MTUs?

I hope you tried to set the Brightbox MTU = 1500 before you did this test?

In reply to a post by eckiedoo:

It reported Fragmentation at the standard setting.
1400 - NO Fragments

What standard setting? Is 1400 the ping size?

In reply to a post by eckiedoo:

1470 - NO REPLY

I hope you mean there was a reply but it was "Packet needs to be fragmented but DF not set"?

In reply to a post by eckiedoo:

So I have left the MTU at 1464

I hope you mean that you left the MTU at 1492 cuz the largest unfragmented Ping was for 1464 and MTU 1492 = Ping 1464 + 28?

Clearer if you copy & paste your results as that page does.

If you were using the newer BrightBox, doesn't this prove that setting its MTU = 1500 has no effect/does not work?

Evening XRaySpeX

Yes, it does look as though I was confused; and that the 1464 etc was the Ping Packet size-

cmd

ping -f -l [packet size] [www.bbc.co.uk]

ping -f -l 1464 www.bbc.co.uk

I will re-try tomorrow, taking account of this correction.

As I recollect, it was "No reply" or very similar and brief.

Strangely though, I still have the impression that the page loading is slightly faster.

Thanks for drawing it to my attention.

Learning progressively, keeping the mind active!

OK, Thanks!

Please remember to set the Brightbox MTU = 1500 before you do this test, else it will have no purpose.

Morning XRaySpeX

I had done more extensive tests; but having problems copying from MSDOS cmd window. (Many years since I used MSDOS regularly!)

The MTU setting in the Bright Box was changed back to 1500 last night; and remains at that.

This morning, I have pinged at-
547
548
549
1400
1463
1464

1465
1499
1500
1501

Up to and including 1464 worked fine.

1465 upwards all timed out, similar to-
"

C:\Users\Alex>ping -f -l 1464 www.bbc.co.uk

Pinging www.bbc.net.uk [212.58.246.92] with 1464 bytes of data:
Reply from 212.58.246.92: bytes=1464 time=39ms TTL=54
Reply from 212.58.246.92: bytes=1464 time=38ms TTL=54
Reply from 212.58.246.92: bytes=1464 time=41ms TTL=54
Reply from 212.58.246.92: bytes=1464 time=38ms TTL=54

Ping statistics for 212.58.246.92:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 38ms, Maximum = 41ms, Average = 39ms

C:\Users\Alex>ping -f -l 1465 www.bbc.co.uk

Pinging www.bbc.net.uk [212.58.246.92] with 1465 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 212.58.246.92:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
"

The major difference today is that I have not seen any regarding the fragmenting of Packets, which did occur on some yesterday.

All of these have been using my HP Pavilion tower VISTA PC directly connected to the Bright Box.

Finally, just checked again that the Bright Box MTU is at 1500 - OK.

Well done! That confirms that apparently setting MTU = 1500 on the newer BrightBox has no effect/does not work.

In reply to a post by eckiedoo:

C:\Users\Alex>ping -f -l 1465 www.bbc.co.uk

Pinging www.bbc.net.uk [212.58.246.92] with 1465 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

That's funny! That's what you get if you leave the "-f" out rather than the "needs to be fragmented" msg, but it still proves the point.

To copy from DOS CMD window: Point at text, R click, Mark, select text rectangle, RETURN,. Then paste where you want it.

My Bright Box has mysteriously changed, it will now no longer save the MTU 1500 only up to 1492.

When I try to save the MTU 1500 I now get�
You�ve entered an unsupported value for �MTU�. Please use a number between 576 and 1492

However I am able to reconfigure with MTU 1500 from my router configuration restore backup copy which is saved with the MTU 1500.


Also I find MTU 1492 is the setting required otherwise it will time out. 1464 + 28 = 1492 MTU.


MTU set at 1492
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Administrator>ping -f -l 1464 www.bbc.co.uk

Pinging www.bbc.net.uk [212.58.244.68] with 1464 bytes of data:

Reply from 212.58.244.68: bytes=1464 time=25ms TTL=53
Reply from 212.58.244.68: bytes=1464 time=25ms TTL=53
Reply from 212.58.244.68: bytes=1464 time=24ms TTL=53
Reply from 212.58.244.68: bytes=1464 time=25ms TTL=53

Ping statistics for 212.58.244.68:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 24ms, Maximum = 25ms, Average = 24ms

C:\Documents and Settings\Administrator>ping -f -l 1465 www.bbc.co.uk

Pinging www.bbc.net.uk [212.58.244.68] with 1465 bytes of data:

Reply from 192.168.13.251: Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.

Ping statistics for 212.58.244.68:
Packets: Sent = 4, Received = 1, Lost = 3 (75% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

=============

MTU set at 1500
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Administrator>ping -f -l 1464 www.bbc.co.uk

Pinging www.bbc.net.uk [212.58.246.93] with 1464 bytes of data:

Reply from 212.58.246.93: bytes=1464 time=26ms TTL=54
Reply from 212.58.246.93: bytes=1464 time=26ms TTL=54
Reply from 212.58.246.93: bytes=1464 time=26ms TTL=54
Reply from 212.58.246.93: bytes=1464 time=26ms TTL=54

Ping statistics for 212.58.246.93:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 26ms, Maximum = 26ms, Average = 26ms

C:\Documents and Settings\Administrator>ping -f -l 1465 www.bbc.co.uk

Pinging www.bbc.net.uk [212.58.246.93] with 1465 bytes of data:

Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 212.58.246.93:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

So it looks the router MTU 1492 is required for Orange network.