Wireshark-users: [Wireshark-users] monitor an STM-1 link
From: Tamás Varga <[email protected]>
Date: Mon, 9 Jun 2008 14:25:14 +0200
Hi Experts,

we want to monitor the traffic of an STM-1 (OC-3) link 
between two Cisco LS1010 ATM switches. For this purpose,
we put an optical splitter in both forward and backward
direction that produces -26 dBm signal level on the
monitored link. The receiver sensitivity on the monitor 
device is stated to be -28 dBm. The receiver link on 
the monitor node does not go up (after administrative shut 
down is disabled).

Questions, if someone has experience:
- is it possible to force link up even no Tx I/F connected?
- does STM-1 need to have bidirectional connectivity?

thanks,
 Tamas
                            
 +---------+                                      +---------+
 |        Tx-----------------T--------(dampener)->Rx        |
 | LS1010  |                 |                    |  LS1010 |
 |        Rx<--(dampener)----------T--------------Tx        |
 +---------+                 |     |              +---------+
                             |     | 
                             v     v
                         +-----------+
                         |Tx Rx Tx Rx|
                         |           |
                         |  Monitor  |
                         |  LS1010   |
                         +-----------+