Stale session or what ?

[BassoProfundo]

Been working over a VPN from home today and thought things were a bit on the slow side. I put it down to our company's atrocious network and didn't think much more of it.

However, at lunchtime(ish), I ditched the [software] VPN, going back to my normal connection. Lo and behold, things were still slow. Time for a speedtest, I thought.

Good ol' BBMax told me that my download speed was something like 600Kbits/sec. Eeek - that's the lowest I've ever had since I joined IDNet. Normally expect anything upward of 4Mbits/sec, with 6.5Mbits/sec not being unusual. Sync rock solid at 8Mb/s. D/S noise margin stable at 13.5dB.

Checked the router logs - no loss of sync and no reconnects. Last time I reconnected was yesterday evening, just to get an up-to-date indication of my download usage.

Hmmm. Odd.

Disconnected at the Radius level and reconnected. Hey presto, d/l speed back to 6.5Mbits/sec.

Now I don't really like mysteries. I'd love to know what's going on here. Could it be one of those infamous "stale sessions" ? What exactly is a "stale session"? How do they arise? Or was there some sort of a problem on one of IDNet's pipes earlier on today? Perhaps the reconnect put me onto a different pipe?

Any insights would be most interesting.

[karvala]

A stale session used to mean that the session table in the router was either full or corrupt, such that you suddenly lost connectivity in practice, while the router was still claiming that you were connected.  The main symptom was a total loss of usable connection; it could never be partial.  These certainly still occur.

These days, though, people talk about having a stale session after their connection slows down or starts behaving in some abnormal fashion, and to be honest, I don't really know what the basis for this is.  It's certainly not a stale session in the traditional sense.  I suspect it's actually something completely different, such a temporary routing problem or a congested VP or Fat Pipe, the latter of which can also be fixed by a new session, so people have confused that with a real stale session, and the term has come to mean basically any problem that seems to be fixed with a reconnection.  That's my guess, anyway.