DUL 20 » History » Revision 13
Revision 12 (laforge, 11/03/2020 03:24 PM) → Revision 13/15 (laforge, 11/03/2020 03:24 PM)
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h1. DUL 20
DUL is a Digital Unit for LTE. It contains the eNodeB function down to the baseband processing.
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h2. Connectors
h3. PWR
48V DC connector. The negative rail is towards the edge of the unit. Also seems to power up fine at 36V
The connectory type is https://www.te.com/usa-en/product-1982299-3.html with associated crimp contacts.
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h3. GPS (RJ45)
Connection for an Ericsson GPS module, contains 1PPS and UART signals
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h3. EC (RJ45)
Environment Control? Probably some RS-485 to control fans, power management, UPS, ...
h3. AUX (RJ45)
?
h3. LMT A (RJ45)
A RS-232 on RJ45 for Local Maintenane use. IT provides access to COLI (COmmand LIne).
The pinout is shown below. Please note it is *different from RBS3000!*, but identical to that of the [[DUG 20]]
|_.RJ45|_.DB9|_.Name|
|1|5|GND|
|2|3|TXD (of PC)|
|3|2|RXD (of PC)|
The [default?] baud rate settings are 9600 8N1.
This port provides RS-232 access to the [[OSE]] shell
h3. LMT B (RJ45)
_Site LAN_ Ethernet, for adminstrative purpose
This is the interface used for configuration of the DUL during installation.
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h3. TN A (RJ45)
_Transmission_ Ethernet, i.e. the back-haul interface for S1. RJ-45
h3. TN B (SFP)
_Transmission_ Ethernet for optical back-haul. Can use normal SFP modules.
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h3. IDL (HSIO)
Inter-DU-Link for cross-connecting multiple DU.
h3. RI A..F (SFP)
Radio Interface (CPRI) using either SFP transceivers for RRU connection or copper interconnect cables for RU.
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h2. Overview Pictures
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h2. Accessing it
h3. SSH via LMT-B
It appears the DUL will always respond to 169.254.1.10/16, no matter what kind of real/other IP address has been set.
You have to use the following SSH config to speak the ancient cipher/key-exchange:
<pre>
Host dul
HostName 169.254.1.10
KexAlgorithms diffie-hellman-group1-sha1
Ciphers 3des-cbc
</pre>
and then log in as the 'rbs' user with 'rbs' password.