FTTC providers w/ sensible routing that don't touch traffic

Hi all,

I recently jumped on the FTTC bandwagon signing up to BT a couple of months ago. While they've been OK, I'm not entirely happy with the throttling side of things and particularly unhappy with routing. I'm in south-west London and to get to other London servers I'm being routed via Sheffield - here's part of a traceroute to my IP:

11 1 ms 1 ms 1 ms 166-49-168-102.eu.bt.net [166.49.168.102]
12 12 ms 11 ms 11 ms core1-te-0-4-0-14.ilford.ukcore.bt.net [62.172.1
13 6 ms 6 ms 6 ms acc2-10GigE-10-0-0.sf.21cn-ipp.bt.net [109.159.2
14 9 ms 9 ms 9 ms 109.159.251.228
15 9 ms 9 ms 9 ms 217.41.169.108
16 10 ms 9 ms 9 ms 217.41.169.198
17 13 ms 13 ms 13 ms 213.120.181.141
18 19 ms 19 ms 19 ms my-super-secret-ip-goes-here

Hops 17-18 show that I'm on fastpath (6ms change) - but hop 13 I think indicates sheffield (sf.21cn-ipp.bt.net).

Just wondering if it's possible to know whether I'm likely to get the same shenanigans happening with other ISPs? I'm frankly a bit confused by BT's network so not sure how much of it is BT retail and how much is BT wholesale.

I'm looking for an ISP which is a little bit more 'enthusiast' focused after previously being with Be - which means no messing about with traffic and actually seeing things like the above as a problem, and not working as intended.

With BT's soon to be announced (to me) price rises, this seems like a good opportunity to move somewhere else.

On the shortlist is AAISP, Zen and potentially Plusnet. BT's usage monitor suggests I use about 80GB a month on average so anything 100GB plus should do the job. Sky isn't an option as I've done the pay for 12 months line rental in advance thing with BT.

So main questions:
- Will the above be fixed by moving ISP, or will it just be hidden from a traceroute?
- Comments on AAISP/Zen/Plusnet or others for an 'enthusiast'/gamer?

Edited by deleted (Wed 29-Aug-12 15:29:24)

How are you going to get out of the 18 month contract?

In reply to a post by Zadeks:

How are you going to get out of the 18 month contract?

Quoting from BT's price change FAQ linked on the tbb homepage:

However if you contact us directly within 10 calendar days of receiving our price change notification you may cease your services without penalty.

I'm no expert on tracert, but surely the route itself is irrelevant? Doesn't tracert just ping each router in turn in the route? So a straight ping would have been the 19ms from your target at that's the slow one.

To me the main indicator there of fast path is the 6ms at hop 13. The difference between two hops doesn't mean anything so far as I know.

Hop 11 is wierd though?

It might be a bit confusing because the traceroute is from a server in London to my home IP address - ie, in reverse to what you might expect!

My explanation is:

Before hop 10 is related to the server that I'm tracerouting from. Since we still have 1ms at hop 11, it's not relevant.
Hop 11 is where we enter the BT network
Hop 12 is more BT network, potentially in Ilford. Looks a bit weird, but subsequent hops make sense so we can ignore it
Hop 13 is in Sheffield. Based on the difference between hop 11 and hop 13 (5ms) this suggests roughly 5ms between Sheffield and London.
Hops 14-16 are mysteriously unnamed.
Hop 17 is the last hop before traversing the VDSL link. The difference between the known sheffield hop and this hop is about 7ms. It seems reasonable to assume that this and maybe hops 14-16 are traffic making its way back down to London to my home.
Hop 18 is my home IP. The difference between 17 and 18 is 6ms, which is consistent with ADSL/VDSL with fastpath turned on. This also suggests that this hop is in London.

As I understand it, tracert hops are not cumulative. You don't add them together to get the round trip time. Each line is the ping from source and return from the router at that hop.

So your logic is wrong, and incidenatlly hop 11 is wierd. It means from source the ping to there was 1ms.

Traceroute is quite a funky program and creates a stream of 3 packets. Each set of 3 has the same 'TTL' and it increases for each set.

The TTL IP parameter tells routers how many hops the packet can make before it has made too many and sould be dropped and a notification sent back. Normally the TTL is set to 32 (I think) and is decremented by each router the packet travels through until it gets to 0.

The first set of packets with a TTL of 1 reach the first router which decrements the TTL counter to 0 and sends back a notification. traceroute reports on this router then increments the TTL to 2 and repeats. These packets make it to the next router and the process repeats until the reporting router is the target device.

Wikipedia has more...

Correct - the ping to hop 11 from the source system was 1ms.

And if hop 17 takes 13ms from system, and hop 18 takes 19ms from the source system, then the time to traverse the link between 17 and 18 is 6ms? I'm not sure what the confusion is!

In reply to a post by driz:

Correct - the ping to hop 11 from the source system was 1ms.

And if hop 17 takes 13ms from system, and hop 18 takes 19ms from the source system, then the time to traverse the link between 17 and 18 is 6ms? I'm not sure what the confusion is!

Therefore the time taken to traverse the link between 12 and 13 was minus 5ms.

In reply to a post by bsdnazz:

Traceroute is quite a funky program ....

Thanks. I remember reading similar a while ago now you describe it. Just doesn't seem to have stuck in my brain .