With this transport you can aggregate contacts from rosters of two (or more) Jabber accounts in single roster. E.g., you can communicate through your GTalk or LiveJournal account, using main account on Jabber.org. For your interlocutors it will be seen as you logged in on this three-accounts manually. Thought actually Gtalk and LiveJournal will be connected through J2J transport.
To make explanations smplier we'll introduce two main concepts: master account and guest account. Master account is that which will be register this transport, guest account is that which will be used through J2J.
In the Username field you must enter username of guest account. Password is a password for guest account. In the Server field you must enter just a hostname of your guest Jabber server.
Value of Port field doesn't follow for change. It must be used when Jabber server uses non-standard port. Because SSL doesn't supported, value 5223 is invalid.
You will receive a subscription request after registration, you must accept it and wait for connection with guest account. When connection is established, J2J will be online.
There are protection from ring registrations on transport, however, it isn't recommended to create such connections.
Using with Google Talk
There will appear an extra option Light first mail-notify in transport options (they could be aceessed via ad-hoc commands). Setting this option on makes the first new mail notification message consistent of number of them only.
Import your contacts from guest-account
If you want to import your contacts from guest-account's roster to your master-account's roster, you can open Discovery-dialog of your Jabber-client, enter JID of your J2J-transport, and add contacts from the "Guest Roster" item. You can use grag and drop technology or context-menu. (drag and drop available in Tkabber и JAJC).
Because, node of JID cannot include "@" char, it needed to use JID-Escaping: all "@" chars is replacing to "%" and "%" replacing to "\%". For example, firstname.lastname@example.org.
If you want to add contact through your guest-account, you must use such format.
At requests of users, auto-answer service is implemented in J2J. Use this for inform your contacts about your new JID or something else.
You need use Jabber-client with ad-hoc commands support, for example, Bombus, JAJC, Tkabber, Gajim or Coccinella. Execute a Options command, check "Enable auto reply for all guest contacts" checkbox and enter text for auto-answer in text area "Text for auto reply". It limited to 1000 chars.
Additional checkbox "Always forward messages to me" means, that messages will be forwarded with enabled auto-answer service too.
Receive message only from Guest roster
You can deny messages from users not from guest-account's roster checking checkbox "Receive messages only from Guest roster".
Where it's used
For a moment, J2J is in use at this servers: