3Com S330 manual CBR Module, Emulation compliant device

CBR Module 231

Each PVC represents the logical circuit being used to connect one PathBuilder S330/S310 port to a remote PathBuilder S330/S310 port. Once you have entered all PVCs, the bridge will learn the network addresses for the local and remote sites and start bridging packets to the correct destination by segmenting the packets into cells which are destined to a remote PathBuilder S330/S310 port. See Figure 168. The ATM network will transport the cells according to the VPI/VCI headers.

Figure 169 shows three PathBuilder S330s configured to provide LAN connectivity between three different LAN segments. Each Ethernet port will run Bridging (Learning) programs to determine if received LAN packets should be passed to the WAN on a specific PVC. In the above example, multi-port bridging software will determine if packets will be passed or dropped. When a packet comes in from LAN 1 port and the Bridge code does not have the destination MAC address associated with one of its logical ports (Ethernet, PVC #1, PVC #2),it will broadcast the packet on all PVCs associated with this port.

Once packets are received from the WAN on specific PVC logical ports, their source addresses will be learned and associated with the logical port. Once you and your carrier have set up PVCs to all remote PathBuilder S330/S310 Ethernet ports, the Bridging code will do the rest.

LAN 1

Figure 169 LAN Connectivity

							PathBuilder
							S330/S310 #2
							LAN
							2
						DS3 UNI 2
Bridge	Forward Known
Table
				ATM		Port P2
	DS3 UNI 1			Switched		Port P3
	Broadcast			Network
		Port P1
PathBuilder	Unknown
S330/S310 #1			Circuits Set Up by the Carrier
		PVC	END1	VPI/VCI1	End2	VPI/VCI2	DS3 UNI 3
		#1	P1	0/200	P2	0/100
		#2	P1	0/250	P3	0/100
		#3	P2	0/250	P3	0/200	LAN
							3
							PathBuilder
							S330/S310 #3

CBR Module	The optional T1-DSX/E1 CBR module provides three T1-DSX or E1 ports (one on
	the PathBuilder S310) and one serial port. This module services traffic generated
	by your existing PBXs, channels, T1/E1 multiplexers, CSU/DSUs, and video
	conferencing devices. This service maps the T1-DSX/E1 service through the AAL1
	adaptation layer over a CBR virtual channel connection (VCC). The VCC is
	established as a permanent virtual circuit (PVC) and mapped from the PathBuilder
	S330/S310’s ATM port to another PathBuilder S330/S310 or an ATM Forum circuit
	emulation compliant device.