Name | Description |
---|---|
MPLS (simple module) |
Implements the MPLS protocol. |
// // (C) 2005 Vojtech Janota // (C) 2003 Xuan Thang Nguyen // // This library is free software, you can redistribute it // and/or modify // it under the terms of the GNU Lesser General Public License // as published by the Free Software Foundation; // either version 2 of the License, or any later version. // The library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. // See the GNU Lesser General Public License for more details. // package inet.networklayer.mpls; // // Implements the \MPLS protocol. // // MPLS module is added between layer 2 and 3 in the OSI model for fast packet // switching. MPLS should be transparent to signalling protocols. Signalling // protocol currently implemented in this simulation is \RSVP-TE. // // Operations // // MPLS packets are represented by the message class MPLSPacket. // The local LIB (Label Information Base) is stored in a LIBTable module // in the LSR. // // For most of the time, the MPLS module will do the label swapping and // message forwarding. Upon receiving a labelled packet from another LSR, the // MPLS first extract the incoming interface and incoming label pair, and then // look up the local LIB table. If an outgoing label and an outgoing interface // can be found, the module will perform appropriate label operations (PUSH, // POP, SWAP) based on the "outLabel" vector containing label and operation // pairs. // // Collaborations // // MPLS module is required to interact with L2 (Link Layer) and L3 (Network // Layer) in the OSI model. In addition, it needs to obtain label information // from the LIB component and label query result from the LDP module. Messages // the model communicates with L2 and Network Layers are L2 packets (PPP, // Frame Relay, ATM, Ethernet, etc.), and \IP native packets. Specifically, // MPLS module encapsulates \IP packet and is encapsulated in L2 packet. // Different L2 protocols may require different methods of encapsulation to // inherit the L2's QoS. This implementation follows a generic approach; it // assumes no information of QoS from the link layer. // simple MPLS { parameters: string classifier; // a module which implements the IClassifier C++ interface @display("i=block/switch"); gates: input netwIn[] @labels(IPDatagram); output netwOut[] @labels(IPDatagram); input ifIn[] @labels(MPLSPacket,IPDatagram); output ifOut[] @labels(MPLSPacket,IPDatagram); }