There are some servers that run custom maps in addition to different modifications. This requires as we all know, that the users connecting need do have Autodownload, or /cg_allowDownload 1, enabled. However, when the client starts downloading a new mod, or a map, it can be very time consuming, especially if they are on a slower connection. On the screen when downloading it tells the current file, it's download speed and estimated download time. So far is all good.
However, the other day when I connected to a server using a modification. It starts downloading files, and one after another large file starts downloading. I wait until it's ready, and then the next one equally large in size comes. I believe it was running the SHA mod (whatever that is). So eventually I didn't want to wait longer, and moved on. The same thing can occur to maps. A person starts a download of the map and if the server is not configured with the sv_dlURL, then the wait for a 25mb map can be tedious since it will use 4-5kb/s as it's download speed.
A suggestion as follows:
During downloads for modifications (if possible) show how many files remain in that specific dir, and their sizes.
During downloads of maps, show a message (configurable by the server admins) where the maps can be downloaded from using a http:// url, pretty much like the mappack variable, but accessible before/during the downloading of the map.
Of course a user can check him/herself where do find maps which the server uses by typing /serverstatus if the server admin has written: sets mappack "
http://openarena.ws/board/index.php?topic=953.0" for example. This however requires the user to connect to the server first..
[edit: some downloads may appear longer than they are..]