Data transfer via Telepathy
A tube is a Telepathy primitive for sending and receiving data, which can be to one person or to a group of people. Tubes can carry reliable byte streams or unreliable datagrams by analogy to TCP or UDP. When a tube is to a group, some different semantics may be more appropriate, since a shared stream is not coherent. It is up to the connection manager how tubes are implemented on top of its protocol.
There are two types of Tubes at present: D-Bus Tubes and Stream Tubes.
D-Bus Tubes provide D-Bus functionality to signal and call methods on everyone in the room.
Stream Tubes wrap TCP/IP sockets and are more suited to streaming data between two participants.
A multi-user tube is represented as a D-Bus bus, and the connection manager makes a mapping between the participants in the tube and D-Bus bus name. Clients can then take advantage of D-Bus's serialisation and the bindings so that they have to do less protocol work.
Stream Tubes allow you to establish TCP connections with contacts or participants in a multi-user chat or conference (MUC).
.---------. |TP client|--|listening socket| B '---------' ^ C | .----------. |Connection| | Manager | A '----------' | _____ __/ \___ ___/ \ / \____ | \ \__ / \ Internets / / \ / \ | ___ / \____/\ / \____/ \____/ ^ | .----------. |Connection| F | Manager |-|listening socket| E '----------' ^ | .---------. |TP client| D '---------'
See Low-level_Activity_API#Stream_Tubes for more documentation.
Tubes Channel Type
In terms of the Telepathy API, we have created a channel type which has methods for enumerating existing tubes and requesting new ones. The channel might be attached to an existing channel (such as a MUC), in which case it will be automatically closed when the underlying channel is closed.
See Telepathy#Proposed Standards for proto XEPs.