In a communication system a communication network is provided, which can link together two communication terminals so that the terminals can send information to each other in a call or other communication event. Information may include voice, text, images or video.
One such communication system is a peer to peer communication system, in which a plurality of end users can be connected for communication purposes via a communications structure such as the internet. The communications structure is substantially decentralised with regard to communication route switching therein for connecting the end users. That is, the end users can establish their own communication routes through the structure based on exchange of one or more authorisation certificates (user identity certificates—UIC) to acquire access to the structure. The structure includes an administration arrangement issuing the certificates to the end users. Such a communication system is described in WO 2005/009019.
Peer-to-peer telecommunications are beneficial to the user as they are often of significantly lower cost than traditional telephony networks, such as fixed line or mobile networks. This may particularly be the case for long distance calls. These systems may utilise voice over internet protocol (“VoIP”) over an existing network (e.g. the Internet) to provide these services, although alternative protocols can also be used.
In a communication system, such as a peer to peer system, client software is installed on end user devices such as personal computers (PCs) to allow the end users to communicate via the communications network. The user interface of the client software can be controlled by the client to display user facilities and to indicate events occurring, such as an incoming call.
The inventors of the present invention have identified that it may not always be possible for the client to display information on the end user device when required, for example when receiving an incoming call. This may be due to a different application running on the device which cannot be interrupted or the user interface of the device, such as the monitor of a PC being switched off. It also may not be possible for the client to display information due to the constraints of the operating system of the device, such as mobile game playing consoles. This prevents the user from using the communication system.
It is therefore an aim of embodiments of the invention to address at least one of the above identified problems.