is reasonable that the broker 11 is charged for the traffic therefore a process for accessing a third party network is further presented here in order to establish an ims session the broker 11 also provides the gateway 14 of each sn 13 with an indirect access token and a session key k session when sending the request for data in one embodiment this session key can be computed as a cryptographic one way function u0192 of the session identifier session_id and the public key k m2mbroker of the broker 11 i e k u0192 session_id k m2mbroker in one embodiment the access token consists of a signed set of critical information for example the token can include the sip uri of the receiver conditions to be met the session identifier the identity of the broker 11 and the identity of the ims provider imsp all signed using the private key sk m2mbroker of the broker 11 i e access token sip uri of receiver conditions session_id broker imsp sign sk m2mbroker fig5 shows a simplified signalling flow example in a situation where an application 12 makes a request for service requiring data from an sn 13 wherein the sn 13 requires the establishment of an ims session using the broker 39 s 11 ims subscription to communicate directly with the tdp 15 in the application environment 10 the steps performed are as follows t 1 as with step s 1 previously described with reference to fig4 the application 12 in the application environment 10 sends a request to the broker 11 asking for a service t 2 as with step s 2 previously described with reference to fig4 the.