Retronetworking » OCTOI - Osmocom Community TDM over IP

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h1. Colocated Hub

This page exists to collect planning about the future colocated OCTOI hub, see #5542

h2. Rackmount units

h3. Central Office server (2U / 67cm)

This is a 2U rack-mount server running all the relevant software.

See [[AVSt_Server]] for more details of the server

h4. Connections

This is a 2U rack-mount server with the following connections:

* Power

** 2x AC power connections (Redundand PSU)

* Ethernet

** 1x RJ45 100-Base-TX BMC

** 2x RJ45 1000-Base-TX

* E1

** 8x E1 to a co-located Cisco AS5400 (see below)

** 1x E1 to a co-located Livingston PM3 (see below)

** 1x E1 to icE1usb/clock-source

h3. icE1usb / E1 clock source (1U / 31cm)

This is a 1U rack mount system containing:

* a PC-Engines APU3 embedded x86_64

* an [[e1-t1-adapter:ICE40_E1_USB_interface|icE1usb]] with a custom RS422 interface board

* a custom rs422 over voltage protection + 12V injection board

This icE1usb acts as a GPS-disciplined clock master.  However, as no acutal RF GPS signal is available in the data centre, we are using an Ericsson [[ericsson-rbs-6xxx:GPS_02]] attached via ~100m of RS-422.

h4. Connections

* Power

** 2x AC power connections (1x APU, 1x RS422/GPS)

* Ethernet

* RS422

** 1x RJ45 towards GPS02 on the roof

h3. Cisco AS5400 RAS Server (2U / 49cm)

h4. Connections

* Power

** 2x AC power connection (redundant PSU)

* Ethernet

** 1x RJ45 Ethernet (100-Base-TX) to internal VLAN

* E1

** 8x E1 (via break-out cable) to AVSt-Server

h3. Livingstion Portmaster 3 (2U / 31cm)

h4. Connections

* Power

** 1x AC power connection

* Ethernet

** 1x RJ45 Ethernet (10-Base-TX) [yes, 10MBps]

* E1

** 1x E1 to AVSt-Server

h2. Roof installation

On the roof of the data centre, the CAT5 cable with RS422 for the GPS03 arrives.

It will be passed through several DIN rail mounted OVP (Over Voltage Protection) circuits before  connecting to the actual DIN-rail mounted Ericsson GPS03

The Ericsson GPS03 has a SMA connector, to which a SMA-male to N-Male coaxial cable is attached.

A Times Microwave LP-GTR-NFF lightning protector (N-female to N-femaile) is used to pass the coaxial cable through the enclosure

An external GPS antenna with N connector is plugged into the LP-GTR-NFF

h3. Overview diagram

This diagram illustrates the parts and connections on the rooftop.  Rectangular objects are DIN-rail mounted.

{{graphviz_link()

graph G {

  subgraph cluster_1 {

    label="Rooftop enclosure";

    rj45splitter [label="RJ45 splitter"];

    GPS03 [label="Ericsson GPS03", shape=rect];

    ovp_rs422_1 [shape=rect];

    ovp_rs422_2 [shape=rect];

    ovp_rs422_3 [shape=rect];

    ovp_12v [shape=rect];

    lp [label="LP-GTR-NFF"];

    rj45splitter -- ovp_rs422_1;

    rj45splitter -- ovp_rs422_2;

    rj45splitter -- ovp_rs422_3;

    rj45splitter -- ovp_12v;

    ovp_rs422_1 -- GPS03;

    ovp_rs422_2 -- GPS03;

    ovp_rs422_3 -- GPS03;

    ovp_12v -- GPS03;

    GPS03 -- lp [label="SMA-male/N-female"];

  }

  antenna [label="GPS Antenna"];

  antenna -- lp [label="RG58 white / N-female"];

  rack [label="Rack in DC"];

  rack -- rj45splitter [label="CAT5"];

}

}}

h2. Software

* Like in the current hub at @laforge's basement, we should run the entire yate / osmo-e1d / dahdi-trunkdev inside a KVM with SRV-IO mapping the PCI devices

h2. Misc / TODO

h3. local verification with modem/ISDN-TA

It would be great if we could somehow verify local calls via the yate / hub excluding the complexity of the TDMoIP to compare calls without TDMoIP to calls with TDMoIP.

Unfortuantely I'm not aware of any really small PBX that would terminate the E1/S2M and offer S0/POTS ports.  Adding antoher 3U for a PBX seems excessive.

Doing calls between PM3 and ASR5400 is of course an option, but ideally we'd have a real physical modem attached via a serial port, and a real HFC-S-USB for test purpose.