Motorola T1/E1 manual Ethernet Throughput

Canopy T1/E1 Multiplexer	September 2004
	T1/E1 Multiplexer FPGA Version 3.4

In a scenario where T1/E1 devices are configured with an external master clock source, each Canopy T1/E1 Multiplexer should be configured in Loopback Timing Mode. Each Canopy T1/E1 Multiplexer will take the timing signal from the incoming T1/E1, derive the clock and then return the clock to the T1/E1 device. The external clock source may be obtained from any number of sources including Carrier services, GPS, or other high- quality clock source.

For example, each of the two PBXs might have a SONET connection from the local telephone company operator. This connection would be used as the master clock source for both PBXs. Alternatively, each PBX could have a Stratum 3 clock source from the same Central Office, or could be connected to GPS receivers.

1.5.5Ethernet Throughput

The Ethernet port to the Canopy BH module is a 100-Mbps full duplex port, transmitting at a throughput rate that does not cause buffer overload in the Canopy modules. The LAN side Ethernet port, connected to the customer LAN, also transmits at 100 Mbps full duplex. The Canopy T1/E1 Multiplexer will insert T1/E1 traffic into the Ethernet bit stream and therefore the Ethernet throughput will be reduced by approximately 2 Mbps for each T1/E1 that is programmed.

The rates for Ethernet throughput for each programmed T1/E1 connection are displayed in Table 11.

Table 11: Canopy BH20 Ethernet throughput for programmed T1/E1 connections

Active	Ethernet Half-duplex	Ethernet Half-duplex
T1/E1	Throughput on LAN	Throughput on LAN
Channels	Port in T1 mode.	Port in E1 mode.
1	5.4 Mbps	5.4 Mbps
2	4.1 Mbps	2.66 Mbps
3	2.34 Mbps	24 Kbps
4	240 Kbps	N/A*

*Due to the bandwidth limitations of the Canopy BH, only 3 E1 channels can be used.

NOTE:

The maximum packet rate in T1 mode is 666 packets/sec. The maximum packet rate in E1 mode is 442 packets/sec. Maximum Ethernet rate occurs when using 1518-byte packet streams.

Issue 3 Page 25 of 73