Browse list lag time.

[Andrew Tridgell]

> So, back to the question of how many minutes (max) out of date a Network 
> Neighborhood can be.  The original word problem went thuslike:
> 
> - If a station gets switched off, the LMB on that subnet will wait three 
>   12-minute cycles before removing the services from the browse list.  At 
>   worst (i.e., the station was switched off immediately following it's 
>   last browser update) the time delay will be 3*12=36 minutes.
> 
> - The LMB syncronizes with the DMB every 15 minutes. Once the DMB has the
>   updated information, it has to send it out to other LMBs.  So the 
>   worst-case on that is 2*15=30.

you forget that this is largely done over UDP. UDP is lossy, at least
on congested networks. If you take that into account then propogation
delays of names can become arbitrarily large.

Personally I just say "about an hour" for the worst case propogation
in a multi-subnet NBT net. There are so many factors that anything
more precise is misleading. Lose one or two packets and it changes,
and Samba uses different time constants in it's announcement-backoff
system so a Samba server can change things too.