3Com 3C63311 Reference Guide - Page 164

152 CHAPTER 4: CONFIGURING PATHBUILDER S330/S310 MODULES, PORTS, AND APPLICATIONS Frame Relay Virtual Circuit Parameters If the serial port is configured as a Frame Relay port, you must set the following virtual circuit parameters in addition to the common Shaper Number, Priority, and Early Packet Discard parameters: Interworking Mode-The Frame Relay/ATM interworking mode: Network or Service. Start/End Frame Relay DLCI-The starting and ending Frame Relay data link connection identifiers: 16...991. These DLCIs are used to identify a Frame Relay local connection. This parameter applies only if the Interworking Mode is set to Network. Encapsulation Mode-The encapsulation data goes around the data packet and is used to identify the packet; enter 1 (Transparent) or 2 (Translation). Transparent-This mode is used for point-to-point frame relay interconnection. See Figure 123. Frame Relay Forum 8 (FRF.8) Service Interworking for this is being implemented. There are two modes at which FRF.8 specifies a mode which is transparent and is in fact 1490 over ATM. Translation-This mode is used in cases when you have ATM devices that do not support 1490 as a protocol across their ATM trunks; for example, when you have a PathBuilder S330/S310 terminating the ATM network at one end and an ATM-ready device, such as a router with an OC-3 UNI, at the other end. Typically these ATM-ready devices do not support 1490 as a protocol across their ATM trunks, so you have to do LLC_SNAP (1483) per FRF.8. Mode 1F does 1490 to 1483 translation. See Figure 124. Figure 123 FRF.8 Transparent Encapsulation Mode DLCI FRR VCC A TM DLCI FRR RFC 1490 RFC 1433 Encapsulated RFC 1490