Establishing a communication session

A method of establishing a secure communication session between a first endpoint and a second endpoint, wherein the first endpoint can contact the second endpoint via a first communication network and via a second communication network, wherein the first communication network is more trusted than the second communication network, the method comprising, at the first endpoint:

• determining that the secure communication session is required;
• establishing a security association with the second endpoint for the communication session on a connection via the first communication network;
• and
• receiving service, provided by the second endpoint, on a connection via the second communication network using the previously established security association;
• wherein
• the step of establishing the security association occurs as part of a step of establishing the secure communication session via said first communication network;
• the first endpoint forces an interruption in the established secure communication session via said first communication network after security association has been established;
• the step of establishing the secure communication session via said first communication network further comprises determining a session identifier;
• the step of receiving service on the connection via the second communication network resumes the previously secure established communication session using the session identifier;
• wherein the first endpoint forces the step of establishing the security association with the second endpoint to occur via the first communication network, and prevents the step of establishing the security association with the second endpoint from occurring via the second communication network.

A method of establishing a secure communication session between a first endpoint and a second endpoint, wherein the first endpoint can contact the second endpoint via a first communication network and via a second communication network, wherein the first communication network is more trusted than the second communication network, the method further comprising, at the second endpoint:

• receiving a request to establish the security association with the first endpoint for the secure communication session;
• establishing the security association between the first and second endpoint for the secure communication session on the connection via the first communication network;
• and
• providing service, to the first endpoint, on the connection via the second communication network using the previously established security association;
• wherein
• the step of establishing the security association with the first endpoint occurs as part of the step of establishing the secure communication session via said first communication network and further comprises determining the session identifier, and
• the step of providing service on the connection via the second communication network resumes the previously established secure communication session using the session identifier.