This page describes the Jabber service hosted at ISI Postel Center.

Jabber is an instant messaging (IM) service based on a set of streaming XML protocols (RFC3920 & RFC3921). Refer to for more information.

Text Version

Contact and support

Mailing List for questions and announcements:

Administrator contact

Server Info

Other Jabber Servers


The following instructions are specific to the Jabber service hosted at the Postel Center. Terminology and examples are based on a couple of popular Jabber clients (Psi & Gaim), but should be similar on other clients.

Jabber Client Software

You need a Jabber client software to use the jabber service. Most IM software also supports Jabber. Check the following link for an extensive list of client software:

Account Registration

Registration is required for every new user to create a new account. Select a Jabber ID (JID) in the form of "[email protected]", replace "foo" with your screen name. Registration is not needed when setting up a new client software with an existing account.

Add a new account in your clients:

  • Psi: check "Register new account" & enter the complete Jabber ID (including "") in the "Jabber ID" field
  • Gaim: enter the screen name (foo) and server name ( separately, then click "Register"

Note that you also need to setup the correct connection parameters described below in order to register.



Connection Settings

The server is open, supports both unencrypted and encrypted (TLS/SSL) connections using non-plaintext (hashed) passwords on the default ports (5222/5223). Default settings on most clients should work. The following settings are recommended:

Select one of the following

  • [x] Use TLS if available / STARTTLS (if the client applications support TLS such as Gaim)
  • [x] Use SSL encryption / Force old SSL (Psi does not support TLS)


  • [ ] Allow Plaintext Login / Allow plaintext auth over unencrypted streams

Ports (for reference only, they are the same as the default on most clients):

  • 5222: TLS (STARTTLS) or unencrypted
  • 5223: SSL

Proxy Setup

This is only needed when you are behind a firewall that blocks the default jabber ports (5222/5223). Please use the following parameters:

  • Type: HTTP Polling (NOT HTTP or HTTP Connect)[*]
  • Host: (blank)
  • Port: 0
  • Polling URL:

[*] Unfortunately, Gaim does not seem to support HTTP Polling, and the server on does not support HTTP (HTTP Connect).

MUC - Multi-User Chat (Chatroom) Service

MUC services is enabled on Users could create chatrooms and invite other users to join.

To create or join a chatroom, use the following parameters:

  • Server/Host:
  • Room: (the name of the chatroom)
  • Handle/Nickname: (the name you will appear in the room)
  • Password: (blank)

Note that to create a chatroom, a user simply needs to join an unused room. You can also get a list of active or permanent rooms either through "Room List" menu or "Service Discovery" on your jabber account. Specify "" as the conference server when prompted. On service discovery, chatrooms are listed under "ejabberd/mod_muc."


Psi Warning on Self-Signed Certificates

Because uses self-signed certificate on the server side for SSL/TLS encryption, some clients will generate warning messages such as this:

"The certificate failed the authenticity test. Reason: Certificate is self-signed."

This only means the certificate for is not signed by any one of the commercial certificate authority ($199+ per year).

There are two ways to avoid the warning message:

(1) Under "Account Properties" => "Preference" tab: Check or select "Ignore SSL warnings".

(2) Download the certificate file from the following location and copy it to the Psi root certificate directory:

Psi root certificate directory:

  • FreeBSD: /usr/local/share/psi/certs
  • Linux:
  • Mac OSX: /Applications/
  • Windows: