ATM transport over multi-protocol label switching

Abstract

User traffic of one type must traverse many diverse networks, each operating by different paradigms and requiring different protocol stacks, before it reaches the destination. MPLS (Multiprotocol Label Switching) is being developed to solve some of the problems which involve the existence of different protocols along the traffic path. There is currently no accepted way of transporting ATM cells over an MPLS domain. New ways of packetizing ATM cells into labeled MPLS packets for transporting over an MPLS domain are described.

1 . A method of transporting ATM cells between two nodes over a multiprotocol label switching domain, hereinafter called an MPLS domain, comprising the steps of: 
 reading an ATM header to obtain attributes of an ATM cell received at a first node, the attributes of the ATM cell including a type of ATM payload,    generating an ATM common header for the ATM cell, the ATM common header mapping the type of ATM payload and other attributes of the ATM cell,    generating an MPLS labeled packet which comprises the ATM common header and the ATM payload, the MPLS labeled packet containing routing information to a second node,    transmitting the MPLS labeled packet to the second node, and    reassembling the ATM cells based on the ATM common header and the ATM payload at the second node.    
   
   
       2 . The method according to  claim 1 , wherein the attributes of the ATM cells comprise one or more than attributes selected from the group consisting of: ATM cell loss priority; VCC or VPC connection; single or bundle cell; congestion indicator; and payload type indicator.  
   
   
       3 . The method according to  claim 1 , wherein the attributes of the ATM cells further comprise an extension bit.  
   
   
       4 . The method according to  claim 3 , wherein the ATM common header has an extension when the extension bit is set.  
   
   
       5 . The method according to  claim 1 , wherein the ATM cells are from different virtual circuit connections (VCC).  
   
   
       6 . The method according to  claim 1 , wherein the ATM cells are from different virtual path connections (VPC).  
   
   
       7 . An apparatus for transporting ATM cells between two nodes over a multiprotocol label switching domain, hereinafter called an MPLS domain, comprising: 
 an ATM header reader for reading an ATM header to obtain attributes of an ATM cell received at a first node, the attributes of the ATM cell including a type of ATM payload,    an assembly module for generating an ATM common header for the ATM cell, the ATM common header mapping the type of ATM payload and other attributes of the ATM cell,    a forwarder for generating an MPLS labeled packet which comprises the ATM common header and the ATM payload, the MPLS labeled packet containing routing information to a second node,    a transmitter for transmitting the MPLS labeled packet to the second node, and    a reassembler for reassembling the ATM cells based on the ATM common header and the ATM payload at the second node.    
   
   
       8 . The apparatus according to  claim 7 , wherein the attributes of the ATM cells comprise one or more than attributes selected from the group consisting of: ATM cell loss priority; VCC or VPC connection; single or bindle cell; congestion indicator; and payload type indicator.  
   
   
       9 . The apparatus according to  claim 7 , wherein the attributes of the ATM cells further comprise an extension bit.  
   
   
       10 . The apparatus according to  claim 9 , wherein the ATM common header has an extension when the extension bit is set.  
   
   
       11 . The apparatus according to  claim 7 , wherein the ATM cells are from different virtual circuit connections (VCC).  
   
   
       12 . The apparatus according to  claim 7 , wherein the ATM cells are from different virtual path connections (VPC).  
   
   
       13 . A computer readable medium storing instructions or statements for use in the execution in a computer of a method for transporting ATM cells between two nodes over a multiprotocol label switching domain, hereinafter called an MPLS domain, the method comprising the steps of: 
 reading an ATM header to obtain attributes of an ATM cell received at a first node, the attributes of the ATM cell including a type of ATM payload,    generating an ATM common header for the ATM cell, the ATM common header mapping the type of ATM payload and other attributes of the ATM cell,    generating an MPLS labeled packet which comprises the ATM common header and the ATM payload, the MPLS labeled packet containing routing information to a second node,    transmitting the MPLS labeled packet to the second node, and    reassembling the ATM cells based on the ATM common header and the ATM payload at the second node.    
   
   
       14 . The computer readable medium according to  claim 13 , wherein the attributes of the ATM cells comprise one or more than attributes selected from the group consisting of: ATM cell loss priority; VCC or VPC connection; single or bindle cell; congestion indicator; and payload type indicator.  
   
   
       15 . The computer readable medium according to  claim 13 , wherein the attributes of the ATM cells further comprise an extension bit.  
   
   
       16 . The computer readable medium according to  claim 13 , wherein the ATM common header has an extension when the extension bit is set.  
   
   
       17 . The computer readable medium according to  claim 13 , wherein the ATM cells are from different virtual circuit connections (VCC).  
   
   
       18 . The computer readable medium according to  claim 13 , wherein the ATM cells are from different virtual path connections (VPC).