[MUD-Dev] Net protocols for MUDing

[J C Lawrence]

On Fri, 20 Mar 1998 10:58:51 PST8PDT 
Shawn Halpenny<malachai at iname.com> wrote:

> On Fri, 20 Mar 1998, J C Lawrence wrote: [...]

>> Given a client which is doing predictive work on the scene it
>> represents to the user, and a server (push or pull) which updates
>> the client with the requisite data for verisimilitude, there is a
>> problem:
>> 
>>   > sc You are near to death.  
>>   > l Bubba is here.  
>>   > kill bubba 
>>   You attack Bubba. // At this instant Bubba's client dissappears.
>>   Bubba pushes you with his shield.  // Predicted first act of Bubba.  
>>   You are dead.  // Result of predicted action.  
>>   Bubba suddenly vanishes!  He has logged out.  
>>   You are alive.
>> 
>> This is of course a variation on the colliding space ships, and
>> suffers from the "who owns the decision" problem described above.
>> The key point however is that prediction only goes so far.

> And what if this _sort_ of thing were a desirable feature?  Think
> Dan Simmons' Hyperion et al. and the Shrike battles where the thing
> just up and disappeared.  Suddenly, you notice your arm is severed
> from your body and the thing is standing next to you, swing
> completed before you had the slightest clue it had returned.

Ahh, but the problem here is not that the feature is possible, but
that it is both unpredictable (not deterministic) and unreliably
reproducable.  With a deterministic system its fairly easy to
implement something like the Shrike.  With the above you might get it
sometimes, and not others -- it all depends on net latencies and dumb
arse luck.

> Admittedly not a strong premise, but it was amusing to think that
> people would be trying to a) obtain/force poor network connections
> to the server, or b) hacking the client to selectively drop packets
> here and there, c) etc., all in hopes of getting the drop on our
> erstwhile hero.

I suspect we'd see a lot more users attempting to interfere with their 
opponents 'net connections.  Raph has already mentioned that this is
(commonly?) done now on UOL (ping storms etc).

Consider the following case:

  Thru various means you identify the IP addresses of a number of
other players (eg the ICQ hole).  You find several that are coming
from the same ISP/subnet.

  Now send a ping packet to that subnet's broadcast address with a
forged source address of the broadcast address.

BOOM!  

PK at your leisure.  There is no bandwith into that net any more.

--
J C Lawrence                               Internet: claw at null.net
(Contractor)                               Internet: coder at ibm.net
---------(*)                     Internet: claw at under.engr.sgi.com
...Honourary Member of Clan McFud -- Teamer's Avenging Monolith...