One of the last parameters you can set for the external component/domain is a protocol which should be used for the connection. At the moment the Tigase server supports two protocols defined in XEP-0114 and XEP-0225 and possibly further protocols.
You don’t have to specify a protocol if you setup a connection in 'listen' mode as the server automatically detects a protocol which is used in incoming connections.
You can specify the protocol which is used for outgoing connections but you have to add one more parameters to the connection string.
There are two possibilities:
An example configuration with protocol specified:
--comp-name-1 = ext --comp-class-1 = tigase.server.ext.ComponentProtocol --external = devel.tigase.org:mucsecret:connect:5270:muc.devel.tigase.org:accept, \ devel.tigase.org:pubsub_pass:connect:5270:pubsub.devel.tigase.org:client
It defines two outgoing connections to external protocols, the first uses the XEP-0114 protocol and the second uses the XEP-0225 protocol.