Enable MCPTT¶

This guide shows how to serve Mission Critical Push To Talk (MCPTT) to subscribers over 4G and 5G, with an external IMS and an MCPTT server. To learn how Ella Core works with the IMS, see IMS Integration.

Prerequisites¶

IMS: an IMS integrated with Ella Core, as in Integrate with an IMS. Its P-CSCF must send the MCPTT ICSI, urn:urn-7:3gpp-service.ims.icsi.mcptt, in the AF-Application-Identifier of MCPTT calls.
MCPTT server: Ella IMS with the mcptt section set in its ims.yaml, or a 3GPP MCPTT server that the IMS reaches and trusts.
MCPTT clients: configured with the MC data network (mcx below) as their MC services APN or DNN.
Radios: support for QCI/5QI 69 and 65.

1. Create the MC data network¶

In the Ella Core UI, go to the Networking page and open the Data Networks tab.

Click Create, enter mcx as the Name, set an IP pool, turn on IMS (voice and mission critical services), and click Create.

2. Create the MC profile¶

Go to the Profiles page and click Create. Enter a Name, e.g. mcptt, and click Create.

Click on the new profile, click Add Policy, and set:

Data Network: mcx.
5QI / QCI: 69 — Mission critical signalling.
Allocation and Retention Priority (ARP): a level between 1 and 8, e.g. 3.
Pre-emption capability: May pre-empt.
Pre-emption vulnerability: Not pre-emptable.

Click Create.

3. Add the MCPTT application server¶

Go to the Operator page and scroll to the IMS section. Under Application Servers, click Add Application Server, click Fill for Ella IMS MCPTT, and click Add.

With another MCPTT server, enter mcptt as the Name, its SIP URI as the Server Name, and an Identity matching its identities, e.g. sip:!.*[email protected].

4. Add the MCPTT filter criteria to the MC profile¶

Go to the Profiles page and click on the MC profile. Click the edit icon next to IMS Filter Criteria.

Under Add from preset, select the MCPTT Preset and click Add. Click Save.

5. Put MCPTT users on the MC profile¶

For each MCPTT user:

Go to the Subscribers page and click on the subscriber.
In Provisioning, click the edit icon next to Profile, select the MC profile, and click Update.
Give the subscriber an MSISDN, as in Enable Voice, and map its IMS public identity, sip:+<msisdn>@<IMS home domain>, to an MCPTT ID on your MCPTT server.

6. Make an MCPTT call¶

On the MCPTT client, make a call to another MCPTT user. The call should connect with audio in both directions.

Ella Core and MCPTT — Enable MCPTT in Ella Core