Why does resetting my ADSL connection sometimes affect my latency?

mks2005 · 27 Oct 2007 at 21:03

During peak times I have ping issues on my ADSL (Virgin Media 8Mb). They seem to abruptly reach leap from 15-25ms to 200ms (to UK websites) or so at random times which seems to correlate with "busier" internet usage periods. However, for example, on Friday night they remained sub 20ms even during the evening. I presume such ping instability is down to lots of people connecting to the exchange?

Another thing I don't understand is that if I take out the ADSL cable and put it back in again, resetting my connection, I can sometimes reconnect and the pings will be much better. Why is this?

Any information would be appreciated.

tolien · 27 Oct 2007 at 21:13

It's nothing to do with the exchange, but rather the connections (aka Centrals) between BTw's network and Virgin's.
Reconnecting might move you from one Central to another, and so from one that's overloaded to one that's less so. You don't have to disconnect the ADSL though - just dropping the PPP session is enough to hop Centrals.

mks2005 · 27 Oct 2007 at 21:18

tolien said:
It's nothing to do with the exchange, but rather the connections (aka Centrals) between BTw's network and Virgin's.
Reconnecting might move you from one Central to another, and so from one that's overloaded to one that's less so. You don't have to disconnect the ADSL though - just dropping the PPP session is enough to hop Centrals.

That makes a lot of sense, thankyou! It's been bothering me for ages now and I knew it was something along those lines. Just one thing though (excuse my lack of networking knowledge) but what do youy mean by "dropping the PPP session"? I thought that meant reconnecting.

tolien · 27 Oct 2007 at 21:20

You can disconnect without losing sync - in essence, that's dropping the PPP session.

Phemo · 27 Oct 2007 at 21:20

mks2005 said:
Just one thing though (excuse my lack of networking knowledge) but what do youy mean by "dropping the PPP session"? I thought that meant reconnecting.

Yes it is just the same ... while keeping ADSL sync. You can usually disconnect/reconnect from within the modem/router's interface - no need to physically disconnect the cable really.

mks2005 · 27 Oct 2007 at 21:37

Thanks guys - should there be other means via the modem-router's interface other than fully rebooting it, or is that what you mean? FYI it's a D-Link DSL-2640B, I can't seem to find a way of reconnecting apart from a reboot button.