Calling other users via Gnomemeeting is available in different forms and is done primarily through the use of URL's.  supports two different kinds of URLs: h323:// and callto://. Callto URL's were used by Microsoft for Netmeeting, and H.323 URLs respect the H.323 standard and are thus the default for .H.323 URL'sH.323 URL's are formatted as such "h323:[user@][host[:port]]"This permits you to:
Call a given host on a port different from the default port which is 1720: h323:seconix.com:1740Call a given user using their respective alias if registered to a gatekeeper: h323:jonitaCall a given phone number if you are registered to a gatekeeper for a PC-To-Phone provider, or if that user has an ENUM record associated to an H.323 URL: h323:003210111222Call a given user using their alias through a specific gateway or proxy: h323:jonita@gateway.seconix.comCall an MCU and join a specific room: h323:myfriendsroom@mcu.seconix.comCALLTO URL'sCallto URL's are formatted as such "callto:[user@][host[:port]]"Callto URL's and H.323 URL's are formatted exactly the same except however callto urls also support ILS lookups through callto URLS of the type: callto:ils_server/user_mail.For example, calling callto:ils.seconix.com/joe.user@somedomain.com will look for the user with the joe.user@somedomain.com email address on the ILS server ils.seconix.com and proceed to initate a call.Callto URL's also support more advanced parameters that are also supported by , all parameters are defined in the Microsoft documentation and should be seperated by a '+' in the URL.There are for example five different ways using  to call the user joe on the gateway gw.seconix.com:
callto:joe@gw.seconix.comcallto:joe+gateway=gw.seconix.comh323:joe@gw.seconix.comcallto:joe if you specified gw.seconix.com as gateway in the  preferencesh323:joe if you specified gw.seconix.com as gateway in the  preferencesSpeed dials is able to associate speed dials with URLs using the address book. You can thus for example associate the speed dial 1 to the URL callto:ils.seconix.com/jonita@jxys.net. That speed dial can then be used as an H.323 or as a callto URL provided that it ends with #. For example, calling callto:1# will call callto:ils.seconix.com/jonita@jxys.net provided that both are associated together in the address book. Quicknet cards users will just have to dial 1 then hit the # key on the phone keypad to trigger the call to the associated URL.
Calling URLs
If you know the URL address of the party that you wish to call, you may enter that URL into the h323: or callto: input box at the top of the screen and press the Connect button; (which looks like an unplugged power socket and is conviently located to the right of the input box). eg: h323:192.168.100.1 and pressing the Connect button would call the user at that respective IP. When the call is connected and you have started communication with your party, the Connect button will now resemble a power plug connected to a socket.If you use literal IPv6-addresses, square brackets are required around them so that the last part of the address won't be mistaken for a port: h323:[2001:638:500:200:210:5aff:fe4c:cfd1] or h323:[2001:638:500:200:210:5aff:fe4c:cfd1]:1740Calling normal phones using PC-to-PhoneWhen you are doing PC-to-Phone calls, you are generally registered to a gatekeeper. It is thus enough to call the remote user using his phone number.Calling users from the online address bookThe online address book will permit you to call online users registered to an ILS server. You can bookmark their callto URL using drag-and-drop or the appropriate menus. See Managing contacts with the Address Book for further information.Calling users from the offline address bookThe offline address book permits you to bookmark your favorite users with their h323 or callto URLs.Calling users from the calls historyThe calls history remembers the callto and h323 URLs that have been used when giving or receiving calls. You can call any user again that is already present in your calls history by double-clicking on his entry in the history.
