RFC 3261 - 18 Transport The transport layer is responsible for the actual transmission of requests and responses over network transports. This includes determination of the connection to use for a request or response in the case of connection-oriented transports.

public class SIPTransportLayer : ISIPTransportLayer, 
	ISIPProtocolLayer

Public Class SIPTransportLayer
	Implements ISIPTransportLayer, ISIPProtocolLayer

public ref class SIPTransportLayer : ISIPTransportLayer, 
	ISIPProtocolLayer

type SIPTransportLayer =  
    class
        interface ISIPTransportLayer
        interface ISIPProtocolLayer
    end