Network Working Group
Request for Comments: 1459
HTML layout by Tatu J. Lund Apr 1997
9. Current problems
There are a number of recognized problems with this protocol, all of which hope to be solved sometime in the near future during its rewrite. Currently, work is underway to find working solutions to these problems.
It is widely recognized that this protocol does not scale sufficiently well when used in a large arena. The main problem comes from the requirement that all servers know about all other servers and users and that information regarding them be updated as soon as it changes. It is also desirable to keep the number of servers low so that the path length between any two points is kept minimal and the spanning tree as strongly branched as possible.
The current IRC protocol has 3 types of labels: the nickname, the channel name and the server name. Each of the three types has its own domain and no duplicates are allowed inside that domain. Currently, it is possible for users to pick the label for any of the three, resulting in collisions. It is widely recognized that this needs reworking, with a plan for unique names for channels and nicks that don’t collide being desirable as well as a solution allowing a cyclic tree.
The idea of the nickname on IRC is very convenient for users to use when talking to each other outside of a channel, but there is only a finite nickname space and being what they are, its not uncommon for several people to want to use the same nick. If a nickname is chosen by two people using this protocol, either one will not succeed or both will removed by use of KILL (4.6.1).
The current channel layout requires that all servers know about all channels, their inhabitants and properties. Besides not scaling well, the issue of privacy is also a concern. A collision of channels is treated as an inclusive event (both people who create the new channel are considered to be members of it) rather than an exclusive one such as used to solve nickname collisions.
Although the number of servers is usually small relative to the number of users and channels, they two currently required to be known globally, either each one separately or hidden behind a mask.
In some places within the server code, it has not been possible to avoid N^2 algorithms such as checking the channel list of a set of clients.
In current server versions, there are no database consistency checks, each server assumes that a neighbouring server is correct. This opens the door to large problems if a connecting server is buggy or otherwise tries to introduce contradictions to the existing net.
Currently, because of the lack of unique internal and global labels, there are a multitude of race conditions that exist. These race conditions generally arise from the problem of it taking time for messages to traverse and effect the IRC network. Even by changing to unique labels, there are problems with channel-related commands being disrupted.