SIU 02¶

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

Connectors¶

POWER¶

The DC input voltage of nominal 24..48V can be applied in any polarity. It uses the same connector like e.g. the DUL 20 or DUG 20 units.

CONSOLE¶

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 hidden.

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>

CLOCK¶

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

Pin	Signal	Function
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?
6	?
7	RS422-A Non-Inverting output	1PPS OUT
8	RS422-A Inverting output	1PPS OUT
9	GND
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://git.osmocom.org/osmo-small-hardware/tree/siu-clock-breakout

E1/T1¶

This is a block of 8 RJ45 connectors, each hosting two E1/T1 circuits.

Pin-out TBD.

Ethernet¶

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.

Further reading¶

• SIU 02 bootlog
• SIU 02 Command Line Interface