There is described a Session Initiation Protocol network entity for operating in a communications channel between a first SIP end point and a second SIP end point in a communication network. A pressurized testing gas is then injected into the combustion chamber so that vacuum at different locations on the engine may be sampled to determine location of the highest gas leakage for identifying possible engine defects corresponding thereto. ABCC is not used for the secondary link, which means that application level TCP will not be informed about congestion on the secondary link. By performing matching in this manner for every pixel in an image, accurate disparity maps can be obtained which are then used in a known image synthesis algorithm to produce novel images of a scene of improved quality. An image is built atop of the adhesive.