Slow BT routing - What is up with it?

chris6273 · 26 Jun 2011 at 01:39

Hi guys,

I have a query. Since around April last year (When I believe my exchange was switched over to IPSC) my ping has more than doubled even though I am still on the same Fastpath profile and still get the same sync.

Here is the problem:

Tracing route to bbc.co.uk [212.58.254.252]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms xxxx
2 <1 ms <1 ms <1 ms xxxx
3 13 ms 13 ms 13 ms 217.47.206.58
4 13 ms 13 ms 13 ms 217.47.206.161
5 21 ms 20 ms 20 ms 213.1.69.42
6 20 ms 20 ms 20 ms 213.120.179.54
7 20 ms 20 ms 20 ms 213.120.179.182
8 20 ms 20 ms 19 ms 109.159.251.233
9 27 ms 27 ms 28 ms core1-te0-4-0-2.ilford.ukcore.bt.net [109.159.251.129]
10 27 ms 25 ms 26 ms core1-pos9-1.telehouse.ukcore.bt.net [194.74.65.114]
11 37 ms 26 ms 26 ms 194.74.65.42
12 26 ms 27 ms 25 ms 212.58.238.153
13 27 ms 26 ms 29 ms rdirslb0.thdo.bbc.co.uk [212.58.224.136]
14 31 ms 25 ms 26 ms virtual3.rbsov.bbc.co.uk [212.58.254.252]

Trace complete.

The hop in bold seems to add another 7ms ping on top of my 13ms ping to the 3rd hop (First BT hop).
I have done some tracerts on some friends' connections who live a few miles away on a different exchange and the 213.1.69.xxx address does not seem to add more than 1ms ping to the route.
I have tried to experiment by modifying the DNS servers on my DG834GT and it resulted in a different IP for the 5th hop in bold but it still had the same delay.

I know this is only 7ms I am talking about but I'm just very curious why there is a delay on that hop.

Does anyone have any idea what BT might have done to it? I used to get 13ms ping to bbc.co.uk but now its more around the 25-27ms range (Around double).

Thanks for your answers

Rroff · 26 Jun 2011 at 01:47

Because BT have been really stupid with their 21CN network and theres only a few entry nodes or whatever they are called and they are badly positioned around the country to - I kid you not my routing goes from South Somerset->Sheffield->Milton Keynes->London now to get out onto the internet on 21CN whereas before I went South Somerset->Reading->London or sometimes South Somerset->Bletchley Park (MK)->London.

EDIT: I believe its not allocated by geography either so 2 people on the same exchange might connect through the BT network totally differently via different nodes on the 21CN and have widely different pings.

chris6273 · 26 Jun 2011 at 01:50

That's funny because I reside in Somerset

Near Bridgwater to be exact.

But why would it be that a connection I tested on an exchange about 3 miles away had no delay on that 213.1.69.xxx hop? Obviously the 2nd hop would be different on different connections but once it enters the 21CN core, it should be in the 1ms range?

Rroff · 26 Jun 2011 at 01:58

AFAIK unless they are pinging 213.1.69.42 exactly theres no guarantee its in the same part of the country - but even if it is... BT's network is just weird these days.

This is my tracert to bbc.co.uk:

Tracing route to bbc.co.uk [212.58.254.251]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms 192.168.1.1
2 10 ms 9 ms 10 ms 217.32.147.98
3 10 ms 10 ms 10 ms 217.32.147.142
4 15 ms 14 ms 15 ms 213.120.181.126
5 15 ms 15 ms 15 ms 213.120.179.50
6 15 ms 14 ms 15 ms 213.120.179.182
7 15 ms 15 ms 14 ms acc2-10GigE-1-3-0.sf.21cn-ipp.bt.net [109.159.251.214]
8 22 ms 23 ms 23 ms core1-te0-12-0-6.ilford.ukcore.bt.net [109.159.251.133]
9 20 ms 20 ms 20 ms core1-pos9-1.telehouse.ukcore.bt.net [194.74.65.114]
10 21 ms 21 ms 21 ms 194.74.65.42
11 23 ms 23 ms 22 ms 212.58.238.153
12 23 ms 23 ms 22 ms rdirslb0.thdo.bbc.co.uk [212.58.224.136]
13 21 ms 21 ms 21 ms virtual2.thdo.bbc.co.uk [212.58.254.251]

Trace complete.

EDIT: Looks like they've sorted the routing out a bit now actually - doesn't drop by MK any more before Ilford (atleast not via any device with an IP).

EDIT2: I ping 213.1.69.42 <13ms so something definitely not right there - if I'm pinging it that low so should you in theory - compare:

6 15 ms 14 ms 15 ms 213.120.179.182 (mine)
7 20 ms 20 ms 20 ms 213.120.179.182 (yours)

chris6273 · 26 Jun 2011 at 02:05

Looks like your first 213.xxx.xxx.xxx address adds quite a bit of latency. I've just put those DNS servers back and I'm being routed though a different 213 address:

Tracing route to bbc.co.uk [212.58.254.252]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms core1-r-0-0-2.evans6273.homeip.net [10.5.15.253]
2 1 ms 1 ms 1 ms core1-r-0-0-1.evans6273.homeip.net [10.5.14.254]
3 13 ms 13 ms 13 ms 217.47.206.58
4 14 ms 13 ms 13 ms 217.47.72.161
5 20 ms 21 ms 20 ms 213.1.69.46
6 20 ms 20 ms 20 ms 213.120.179.26
7 21 ms 21 ms 20 ms 213.120.179.178
8 28 ms 26 ms 27 ms acc1-10GigE-10-3-0.sf.21cn-ipp.bt.net [109.159.251.97]
9 31 ms 30 ms 27 ms core1-te0-4-0-2.ealing.ukcore.bt.net [109.159.251.1]
10 26 ms 24 ms 25 ms core1-pos1-0-0.telehouse.ukcore.bt.net [62.6.201.82]
11 26 ms 25 ms 25 ms 194.74.65.42
12 27 ms 27 ms 27 ms 212.58.238.153
13 25 ms 26 ms 25 ms rdirslb0.thdo.bbc.co.uk [212.58.224.136]
14 27 ms 26 ms 27 ms virtual3.rbsov.bbc.co.uk [212.58.254.252]

Trace complete.

Still adds around 7ms. This routing is rubbish! 13-14ms to get from the First BT hop (Exchange Router) to the BBC is simply ridiculous!

Rroff · 26 Jun 2011 at 02:07

Yeah I agree - unfortunatly I think a lot of its BT saving money apparently theres not a lot of redundancy in the network these days.

When I first moved (back) down here I pinged the bbc at 8-9ms!.

chris6273 · 26 Jun 2011 at 02:16

Yeah, I miss the good ol' routing

I guess I'm going to have to wait until a decent LLU provider shows up at my exchange - Nether Stowey (WWNETH) Before I can expect some decent low pings again.

Rroff · 26 Jun 2011 at 02:22

Oh harsh:

"21CN WBC status: Not available" so I guess that means you only get the old 8Mbit down 448kbit up ADSLMAX product? but still get the crappy 21CN routing

chris6273 · 26 Jun 2011 at 02:27

Yup, it's not fair lol. Only thing I can hope is if 21CN WBC gets enabled I get routed better as it will be new equipment.etc.

One thing which is not fair is, look at this exchange around 3 miles away (Note its customer line number and what providers it has): http://www.samknows.com/broadband/exchange/WWHOLF

Rroff · 26 Jun 2011 at 02:34

Not really missing much tho talk talk and orange aren't great alternatives :S hopefully as the FTTC roll out moves forward they will start sorting out routing a bit.

chris6273 · 26 Jun 2011 at 02:38

I guess but it shows how messed up these things get around here. I hope this FTTC reaches here soon (Which it probably won't because BT probably class my exchange like most around here - not viable. Maybe that funding for Somerset from the government might help)?

Locky · 26 Jun 2011 at 06:20

Tracing route to www.bbc.net.uk [212.58.244.70]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms api.home [192.168.1.254]
2 6 ms 5 ms 6 ms 217.32.144.162
3 7 ms 7 ms 6 ms 217.32.144.190
4 8 ms 8 ms 8 ms 213.120.181.50
5 8 ms 8 ms 8 ms 217.32.25.46
6 8 ms 7 ms 8 ms 217.32.25.182
7 8 ms 8 ms 8 ms 109.159.251.235
8 16 ms 15 ms 15 ms core1-te0-4-0-2.ilford.ukcore.bt.net [109.159.25
1.129]
9 14 ms 14 ms 14 ms core1-pos9-0.telehouse.ukcore.bt.net [62.6.201.1
18]
10 14 ms 14 ms 14 ms 194.74.65.42
11 13 ms 13 ms 13 ms 212.58.238.153
12 14 ms 14 ms 14 ms 212.58.239.62
13 14 ms 15 ms 14 ms 212.58.251.44
14 12 ms 13 ms 12 ms bbc-vip115.telhc.bbc.co.uk [212.58.244.70]

M ping almost doubles at Ilford.

cp88 · 26 Jun 2011 at 09:29

C:\Users\.>tracert bbc.co.uk

Tracing route to bbc.co.uk [212.58.254.252]
over a maximum of 30 hops:

1 1 ms <1 ms <1 ms BTHUB3 [172.16.0.1]
2 7 ms 6 ms 6 ms 217.32.142.5
3 7 ms 7 ms 7 ms 217.32.142.30
4 7 ms 7 ms 7 ms 213.120.163.14
5 7 ms 7 ms 7 ms 217.32.27.50
6 7 ms 7 ms 6 ms 217.32.27.182
7 7 ms 7 ms 7 ms acc2-10GigE-9-2-0.mr.21cn-ipp.bt.net [109.159.25
0.228]
8 17 ms 15 ms 15 ms core1-te0-4-0-0.ilford.ukcore.bt.net [109.159.25
0.129]
9 14 ms 13 ms 14 ms core1-pos9-1.telehouse.ukcore.bt.net [194.74.65.
114]
10 14 ms 14 ms 14 ms 194.74.65.42
11 14 ms 14 ms 14 ms 212.58.238.153
12 14 ms 13 ms 14 ms rdirslb0.thdo.bbc.co.uk [212.58.224.136]
13 14 ms 14 ms 14 ms virtual3.rbsov.bbc.co.uk [212.58.254.252]

Trace complete.

Damn you ilford!!

ots3go · 26 Jun 2011 at 09:49

And I thought Virgin taking 6 hops to get into the outside world was bad.

cp88 · 26 Jun 2011 at 09:52

Atleast BT pings are stable tho

GhostlyPea · 26 Jun 2011 at 09:53

On be* for comparison:

C:\Users\Chris>tracert -d bbc.co.uk

Tracing route to bbc.co.uk [212.58.254.252]
over a maximum of 30 hops:

1 36 ms 99 ms 99 ms 10.0.1.1
2 * * * Request timed out.
3 * 17 ms 16 ms 10.1.3.178
4 17 ms 17 ms 17 ms 10.1.2.158
5 17 ms 16 ms 16 ms 195.66.226.103
6 17 ms 16 ms 16 ms 212.58.238.149
7 17 ms 16 ms 16 ms 212.58.224.136
8 17 ms 16 ms 16 ms 212.58.254.252

Trace complete.

16ms is pretty good for me - used to be on BT and it was crap.

- Pea0n

ots3go · 26 Jun 2011 at 09:56

cp88 said:
Atleast BT pings are stable tho

Thankfully my pings have been solid for almost a year on Virgin.

. However, my time on BT's network was shocking.

TB1968 · 26 Jun 2011 at 09:59

Rroff said:
Because BT have been really stupid with their 21CN network and theres only a few entry nodes or whatever they are called and they are badly positioned around the country to - I kid you not my routing goes from South Somerset->Sheffield->Milton Keynes->London now to get out onto the internet on 21CN whereas before I went South Somerset->Reading->London or sometimes South Somerset->Bletchley Park (MK)->London.

EDIT: I believe its not allocated by geography either so 2 people on the same exchange might connect through the BT network totally differently via different nodes on the 21CN and have widely different pings.

Well not really an issue with 21CN's placement of their metro nodes (yup think thats what they called them), they have strategically placed them in all the right places, just that 21CN sucks to start with

They are connected by SDH transmission, which as we all know uses light (its pretty damned quick

) its more likely just the far end kit or the cables in between that sucks (we all laughed at 21CN when they announced it, it doesnt work, it never will in its present form, it was a complete waste of 10 billion quid, even the first site that went live which was in wales had a 95% failure rate when they switched it over, hence why the phones still run on the old System X and AXE10 exchanges).
Improvement will come though with the introduction of fibre to cab technology, any cable in the middle will always slow things down though

cp88 · 26 Jun 2011 at 10:02

7 7 ms 7 ms 7 ms acc2-10GigE-9-2-0.mr.21cn-ipp.bt.net [109.159.25
0.228]
8 17 ms 15 ms 15 ms core1-te0-4-0-0.ilford.ukcore.bt.net [109.159.25
0.129]

Theses 2 look to be in the same data centre? yet the MS doubles.

ots3go · 26 Jun 2011 at 10:04

You can't really tell if they're in the same datacentre from that. Never know what subnet's they're using. More than likely a lot of /30 jobbys.