Neighbor Discovery via PPP
Tellabs
Work has been progressing in the Common Control and Measurement Protocol (CCAMP) working group on the application of MPLS technology to non-packet switching networks. Development of the Generalized MPLS (GMPLS) signaling draft [1] has allowed for Optical, SONET/SDH, and spatial switching systems to be controlled using IP protocols. In a GMPLS network, the path that a TDM connection will use is developed using constraint based routing. The developed route utilizes TDM link state information announced via OSPF or IS-IS by other nodes in the network. However, a node cannot advertise the existence of a link without first identifying the remote node connected to the link and the capabilities of the neighboring node. In a packet network, this function would typically be accomplished using OSPF or IS-IS Hello messages repeated every 10 or so seconds. However, the TDM link cannot transmit similar messages because the port terminating the link cannot be shared between a TDM service user and the OSPF/IS-IS termination function.