3com S330 User Manual

C

HAPTER

 4: C

ONFIGURING

 P

ATH

B

UILDER

 S330/S310 M

ODULES

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PPLICATIONS

To configure the OC3/STM-1 port, follow these steps:

1 From the Configuration Management menu, shown in Figure 50, select 

[1] Manage Card to display the List Card menu, shown in Figure 51.

2 From the List Card menu, select [4] OC3 UNI to open the SONET UNI 

Configuration menu, shown in Figure 74. This menu displays the current 
configuration for the OC3/STM-1 port and provides options that allow you to 
change certain settings.

Figure 74   Configuring the OC3/STM-1 Port

3 Set the following parameters as desired:

Admin. Status—Administrative status: Out of Service or In Service.

Sonet Interface Mode—The SONET interface supports two modes: OC3 and 
STM-1. Choose the mode used at your location. OC3 is used most often in the 
United States, while STM-1 is common in other countries.

ATM Payload Scramble—Enables (yes) or disables (no) payload scrambling for 
the OC3/STM-1 port. The default is disabled (no). Payload scrambling is a 
technique used to avoid certain transmission equipment behaviors (for example, 
erroneous alarm conditions) that are caused by sensitivity to certain bit patterns in 
the ATM payload. When you set payload scrambling to yes, the ATM Payload 
Scramble scrambles the 48 byte payload in outgoing cells in a defined manner and 
unscrambles the payload in incoming cells. The payload scramble settings must 
match at the two ends of the OC3/SDH trunk.

Timing Source—The timing source for the OC3/STM-1 transmit clock.

Loop—Configures the OC3/STM-1 port interface to use the input port Rx clock 
as the timing source; timing is received from the service “loop.” Select Loop if 
the OC3/STM-1 port is used for the network/carrier service termination, in 
which case the carrier (the service “loop”) typically provides the timing source.

System—Configures the OC3/STM-1 port interface to use the internal system 
clock as the timing source.