What is created between two DTEs in a frame relay network?
Virtual Circuit is Created. Each circuit is known by its DLCI. i.e. Data Link Connection Identifier.
There are various differences between X.25 and Frame Relay. The most significant are: 1. Call Control X.25 connection establishment and release (call control) use in-band signaling within the same virtual channel used for user data transmission causing additional overhead. Frame Relay call control uses separate virtual channels identified by reserved DLCI using the LMI (Local Management Interface) protocol. 2. Routing vs. Switching X.25 performs packet switching on OSI layer 3 (network layer); Frame Relay performs…
Frame relay and PPP is used with WAN encapsulation. Frame Relay most closely compares to the OSI data link layer (Layer 2). If you remember that the word "frame" describes the data link layer protocol data unit (PDU), it will be easy to remember that Frame Relay relates to OSI Layer 2. Like other data-link protocols, Frame Relay can be used to deliver packets (Layer 3 PDUs) between routers.
Frame Relay is a WAN (Wide Area Network) encapsulation protocol. It is considered a Multi-Access-Non-Broadcast medium. Each router has a DLCI number that will uniquely identify a specific route, however that DLCI is locally significant only. Data from your router will be sent into the Frame-Relay cloud, there the frames are switched (OSI layer 2). The path traveled is only there when it is needed. Your Service Provider might be switching towards MPLS though.