PDF user manual for CopperEdge 150

Not all translations described by the FRF.8.1 specification areimplemented. Translations are implemented for Frame RelayPDUs with:• NLPID=0x80, which include but are not limited toBridged PDUs (802.3 protocol) and Other routed PDUs(AppleTalk data, AppleTalk ARP, IPX, Inverse ARP butnot ARP)• NLPID=0xCC, which are Routed IP Version 4 PDUs• NLPID=0x08, Connection oriented protocols (Q.933/Q.2931NLPID) PDUs that include but are not limited to SNAPackets that do not fall into these categories will be discarded.PPP Translation and Transparent Forwarding ModesThe PPP-translation forwarding mode supports RFC-1973 toRFC-2364 interworking. PPP-transparent forwarding modesupports RFC-1973 to RFC-1973 interworking. At present,RFC-2364 to RFC-1973 and RFC-2364 to RFC-2364 interworkingare not supported.RFC-2364 actually specifies two encapsulations, the Null (VCMultiplexing) and the Logical Link Control (LLC) encapsulations.ATM based line cards and WAN interfaces in the CE150support both RFC-2364 encapsulations.To convert an RFC-1973 frame to RFC-2364, the flag and Q.922header are stripped away. For the RFC-2364 Null encapsulation,Control and NLPID are removed as well. For the RFC-2364LLC encapsulation, an LLC header is prepended to the frameand the NLPID is retained. With both RFC-2364 encapsulations,an optional pad and a CPCS-PDU trailer are appended tothe frame at the ATM driver level. The process is reversed toconvert an RFC-2364 frame to RFC-1973.The following frame-based line cards and WAN interfaces in theCE150 support RFC-1973 encapsulation:• SDSL• T1• DS3 Frame• Quad T1The following ATM-based line cards and WAN interfaces in theCE150 support RFC-2364 encapsulation:• G.lite• G.dmt• DS3 ATM&KDSWHU$GYDQFHG&RQILJXUDWLRQ