Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: Oldjim on September 01, 2016, 11:02:29 AM

Title: What happens to the connection when BT fiddle at the exchange
Post by: Oldjim on September 01, 2016, 11:02:29 AM: (https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.thinkbroadband.com%2Fping%2Fshare-large%2F690ec6c24699cc7b55845da1ff77de2a-01-09-2016.png&hash=8e9679db8bfd6525eb211cf789a883edb103f89f)
and the sync didn't drop so could BT fiddling have caused a PPP drop only for FTTC
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Black Sheep on September 01, 2016, 01:24:53 PM: No. :)
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Weaver on September 01, 2016, 01:35:26 PM: So it's a few large blips further out in the network then?
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Weaver on September 01, 2016, 01:43:33 PM: I'm interested to see that you are in fact using the same kit to provide the continuous link testing as I am, a Firebrick 6000 ping box. Yours is from the Thinkbroadband people and presumably is doing IP ICMP pings, whereas the same kind of box, at my ISP, Andrews & Arnold, is sending a different type of packet, PPP LCP ‘pings’, and works at a lower level than IP - that's the difference.
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Oldjim on September 01, 2016, 02:14:47 PM: @blacksheep
According to Plusnet staff as the sync is at the cab not the exchange some work at the exchange may cause a PPP drop without creating a resync
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Black Sheep on September 01, 2016, 03:23:46 PM: I've no idea how that could be ....... the path the broadband takes from the Cab is different to what the dial-tone takes, ((ie: one is fibre the other is Cu/Ali).

*Afterthought - Unless of course fibre engineers were messing around ??
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Weaver on September 01, 2016, 03:55:17 PM: PPP terminates at the ISP, is that correct? Does the exchange kit even know that PPP exists? I may well be completely wrong, so someone please set me straight. Would like to see a protocol diagram. Apologies ???
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Oldjim on September 01, 2016, 04:01:29 PM: From my - very limited - understanding (and probably total bollocks) the sync from the user to the cab is controlled by the cab which received everything via the fibre connection to the exchange
It is possible that once it gets to the exchange it connects to the main backbone via the same link as the normal ADSL and if someone was mucking about with the connections to this backbone it could have the effect I saw
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Weaver on September 01, 2016, 04:09:15 PM: > the sync from the user to the cab is controlled by the cab

Not bollocksat all. Quite correct.

I think PPP is possibly relayed by the BRAS ? A man in the middle? Someone will put me right.
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: ejs on September 01, 2016, 04:48:00 PM: The outages were possibly something to do with the BTWholesale planned maintenance that Plusnet post an update about each week. I don't normally bother to read them, but there is very little in the latest one.

@Weaver

Where the PPP connection is terminated depends on how the ISP chooses to have it done. Plusnet used to have everything tunnelled to them using L2TP, and then the PPP connections ended on the Plusnet gateways. However, if you're on Plusnet's new network and don't have a static IP, then your PPP connection terminates on the BTWholesale BRAS.
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Oldjim on September 01, 2016, 04:50:26 PM: looking Zen give a bit more information https://status.zen.co.uk/broadband/maintenance-outage-details.aspx?reference=312599
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: Weaver on September 01, 2016, 06:44:16 PM: @ejs Many thanks. In the case where it terminates on the BT Wholesale BRAS, what happens beyond the BRAS?
Title: Re: What happens to the connection when BT fiddle at the exchange
Post by: ejs on September 01, 2016, 07:22:35 PM: Then I believe it's routed IP traffic between the BRAS and ISP. I've never been particularly interested in all the stuff that goes on beyond the DSLAM though, APs and EPs and the rest of the WBC bits. There's information about it in BT SIN 472.