Avaya 555-245-600 사용자 설명서

This hypothetical implementation shows the Dallas corporate office connected to three branch 
offices in a common star topology (or hub and spoke). Each office connects to a LEC CO over a 
fractional T1 circuit, which terminates onto a Frame Relay port at the CO, and onto a Frame 
Relay capable router at the customer premise. The port rates and the access circuit rates 
match. PVCs are provisioned within the Frame Relay network between Dallas and each branch 
office. The CIR of each PVC is sized so that it is half the respective port rate, which is a 
common implementation. Each branch office is guaranteed its respective CIR, but it is also 
allowed to burst up to the port rate without any guarantees.
The port rate at Dallas is not quite double the aggregate CIR, but it does not need to be, 
because the expectation is that not all three branch offices will burst up to the maximum at the 
same time. In an implementation like this, the service is probably negotiated through a single 
vendor. But it is likely that Dallas and Houston are serviced by the same LEC, and that the 
Frame Relay is intra-lata, even if it was negotiated through an IXC, such as AT&T, WorldCom, 
or Sprint. The service between Dallas and the other two branch offices, however, is most likely 
inter-lata.

The obstacle in running IP Telephony over Frame Relay involves the treatment of traffic within 
the CIR and outside of CIR, commonly termed the “burst range.”