Massive Latency problems

Target Name: www.bbc.co.uk
IP: 212.58.246.91
Date/Time: 03/06/2013 20:29:47 to 03/06/2013 20:29:56

1 3 ms 3 ms 3 ms 3 ms 3 ms 3 ms 3 ms 3 ms 3 ms 3 ms home.gateway.home.gateway [192.168.1.254]
2 25 ms 131 ms 29 ms 292 ms 51 ms 16 ms 26 ms 18 ms 24 ms 18 ms lo0-central10.ptn-ag01.plus.net [195.166.128.190]
3 16 ms 15 ms 16 ms 16 ms 15 ms 31 ms 16 ms 15 ms 15 ms 16 ms link2-central10.ptn-gw02.plus.net [84.93.248.130]
4 46 ms 15 ms 15 ms 15 ms 15 ms 18 ms 15 ms 15 ms 18 ms 15 ms xe-1-2-0.ptw-cr02.plus.net [212.159.1.30]
5 16 ms 15 ms 16 ms 34 ms 19 ms 19 ms 15 ms 15 ms 15 ms 16 ms ae2.ptw-cr01.plus.net [195.166.129.4]
6 15 ms 16 ms 16 ms 16 ms 15 ms 15 ms 15 ms 15 ms 15 ms N/A kingston-gw.thdo.bbc.co.uk [212.58.239.6]
7 * * * * * * * N/A N/A N/A [-]
8 16 ms 17 ms 58 ms 53 ms 16 ms 24 ms 17 ms 16 ms 27 ms N/A ae0.er01.cwwtf.bbc.co.uk [132.185.254.93]
9 17 ms 27 ms 28 ms 17 ms 18 ms 16 ms 18 ms 18 ms 16 ms N/A [132.185.255.164]
10 16 ms 16 ms 16 ms 16 ms 16 ms 16 ms 16 ms 15 ms 16 ms N/A bbc-vip012.cwwtf.bbc.co.uk [212.58.246.91]

Ping statistics for www.bbc.co.uk
Packets: Sent = 10, Received = 10, Lost = 0 (0.0%)
Round Trip Times: Minimum = 15ms, Maximum = 16ms, Average = 15ms


lo0-central10.ptn-ag01.plus.net hitting 500ms

Edited by Stanman_24 (Mon 03-Jun-13 20:31:28)

ahhh good.

Plusnet still have the overloaded pipe problem then where they have to disconnect users and let them reconnect on less congested connections I assume?

If the pipe was overloaded/congested - in terms of throughput to/from other places - then I'd expect to see some increased ping latencies from all other places, not just PN's own edge router.

PN themselves have said that ICMP packets are treated as titanium level traffic in their traffic management nodes. I'd expect them to transit through the routers on the fastest possible speeds.

However, an ICMP ping packet targeted *at* one of the edge routers is something different - it needs to be processed and answered from within the router, rather than being transited by the router. A subtle difference.

So a delay in a packet that was targeted at the edge router might indicate that it has other processing going on, independent of "just" transit routing, and the ICMP response was delayed for those reasons.

I'd be more concerned if packets that transit the edge routers were being delayed.

Agreed.

It is only if the step at a node is then continued to most or all of the later nodes that there is a problem.

If the particular node is (mostly) the only one with a high value that simply means it has better things to do, i.e. passing genuine traffic through, than respond to somebody pinging it. Which is why many are configured not to respond at all - the ones that time out.

Edit:-

Ping statistics for www.bbc.co.uk
Packets: Sent = 10, Received = 10, Lost = 0 (0.0%)
Round Trip Times: Minimum = 15ms, Maximum = 16ms, Average = 15ms

Looks pretty good to me.

Edited by RobertoS (Mon 03-Jun-13 22:37:10)

look at my bqm

That's more meaningful . Have you tried a router disconnect t see if you get a different gateway? Also, what is being done on your connection?

Which product are you one? A "new" unlimited, or a legacy one?

unlimited

you will see i did a resync as my latency dropped about 3 ms

hopefully nothing major

I did wonder where that drop in the base latency had come from .

On FTTC re-sync's can be so quick as not to drop the session at the ISP. If I force one I always make sure I break the connection for at least 20 seconds before starting the re-sync.

There is another reason for my doing this this as well. The PlusNet Current line speed doesn't get updated if the session isn't dropped, so the "new" BT IP Profile doesn't get reflected into it. That can cause issues on below 80 (or 40) Mbps connections.

A quick scan of the plusnet forums Icame accross this TBBQM in a related thread , looks like congestion setting in somewhere Not looking good
And was Plusnet Gateway ptw-ag04

Edited by tommy45 (Tue 04-Jun-13 01:58:45)

From what I can see, ptn-ag01 and ptw-ag04 were looking fine last night. No significant latency or dropped packets on our monitoring.

I'll have a bit of a dig and see if I can see anything further.