The SIU (Site Integration Unit) is an optional element in the transport network of the Ericsson 2G RAN.It includes functionalities like
- 16 E1/T1 lines
- 8 Gigabit Etghernet ports (up to 8x copper, up to 4x optical/SFP)
- Ability to route IP/Ethernet traffic over E1
- Ability to convert from Abis/E1 or PacketAbis/E1 to Ericsson PacketAbis/IP (L2TP)
- Synchronization for E1
- from SyncE
- from IEEE PTP
- from 1PPS input
This is an RJ45 Ethernet port, internally connected to a BCM5221 Fast Ethernet PHY
It is configured to a fixed IP address of 192.168.1.1/24 and provides telnet + SSH access.
The default user name is
admin; the default password is
You will get access to a command line interface:
Trying 192.168.1.1... Connected to 192.168.1.1. Escape character is '^]'. login: admin Password: STN CLI - ready OSmon>
This is a 10P10C western connector, sometimes also called RJ50.
Internally, it connects to some protection circuitry and then to a series of three ST2485EC RS-422 transceivers.
The pinout is as follows
|1||RS422-C Non-Inverting input|
|2||RS422-C Inverting input|
|3||RS422-B Non-Inverting input||?!?|
|4||RS422-B Non-Inverting input||1PPS IN?|
|5||RS422-B Inverting input||1PPS IN?|
|7||RS422-A Non-Inverting output||1PPS OUT|
|8||RS422-A Inverting output||1PPS OUT|
|10||+12V DC output||Supply external GPS?|
There is a OSHW design for a breakout-board with RS-422 transceivers so you get a CMOS level 1PPS input and output: https://gitea.osmocom.org/electronics/osmo-small-hardware/src/branch/master/siu-clock-breakout
This is a block of 8 RJ45 connectors, each hosting two E1/T1 circuits.
This is a block of 8 RJ45 conncetors, each supporting one 10/100/1000 Mbps Ethernet port.
Four of the Ethernet connectors can alternatively be used with a SFP optical transceiver.