What is a PoC server?
A PoC server is the central software of a push-to-talk over cellular service. Radios and phones connect to it over a mobile network or Wi-Fi, and it checks who may talk, keeps the talk groups, grants the floor and sends the voice to every listener. It is a program, not a radio.
The standards give the same role two names. OMA, the standard behind classic PoC, calls it a PoC Server; 3GPP, the standard behind mission-critical push-to-talk, calls it an MCPTT server.12 A PoC radio service is a subscription to such a server together with the apps on the radios, and the PoC radio is the client.
What does a PoC server do during a call?
A PoC server handles every step of a call except the radio link. It admits the user to a group, checks permission, decides who may talk, copies the talker's voice to each member and can log the call. The 3GPP and OMA documents split these jobs between call control, floor control and media distribution.12
| Function | What the server does |
|---|---|
| Registration and groups | Calls reach the server through the SIP core; it authorizes the user for the group and tracks which groups the user has joined (affiliation), including a maximum number of joined groups per user1 |
| Talk groups | Resolves a group ID to its members and their affiliation status, using the group management server1 |
| Floor control | Grants, denies or queues floor requests by priority and may limit how long a user holds the floor1 |
| Voice relay | The controlling function distributes the media to all participants; each call has exactly one controlling server12 |
| Presence | Presence information about a client can be published by the PoC Server on the client's behalf and is kept by a presence server2 |
| Location | The client reports where it is; the server checks the user's privacy policy before giving the location to other participants1 |
| Recording | The server manages recording through a recording server; WalkieFleet records all voice calls on the server as MP3 and video calls as MKV13 |
| Radio gateway | WAVE PTX On Prem lists wireline interoperability with ASTRO 25, P25, DIMETRA and MOTOTRBO systems11 |
Dispatcher consoles are clients of the same server; they are covered in the dispatch software guide. Gateways that link conventional radios over IP are explained in radio over IP.
How does a PoC server differ from an MCPTT server?
They do the same job under two standards. OMA PoC, version 2.1 approved in August 2011, defines a PoC Server on an IMS core. 3GPP MCPTT, built for public safety on LTE, defines an MCPTT server with emergency-call priority and an off-network mode. Both split the server into a controlling and a participating role.12
| OMA PoC | 3GPP MCPTT | |
|---|---|---|
| Server name | PoC Server, in the Controlling or Participating PoC Function2 | MCPTT server, in the controlling or participating role1 |
| Network | SIP/IP core, 3GPP or 3GPP2 IMS2 | LTE with the common services core of TS 23.2801 |
| Floor control | Talk Burst Control and Media Burst Control in the controlling function2 | A floor control server located with the MCPTT server1 |
| Typical users | Commercial push-to-talk | Public safety, utilities and railways1 |
The controlling server keeps one session per participant and talks to each client through that client's participating server.2 One PoC Server can hold both roles at the same time.2 The MCPTT page covers the standard in full.
Cloud server or your own server: which fits?
Choose a vendor cloud when you want no server to run. Choose your own server when the network is closed, the data must stay inside your perimeter or you want control over updates. Vendors that offer both often keep some features for the cloud, so compare the feature lists first.913
| Aspect | Vendor cloud | Your own server |
|---|---|---|
| Who runs it | The vendor | You run the hardware and maintenance;9 WAVE PTX On Prem gives control over update and maintenance activity11 |
| Internet | Clients and server meet over the internet | Zello Enterprise Server works on a local intranet without internet;9 GroupTalk On Premise is for private 4G or 5G networks without internet access14 |
| Data location | The vendor's data centers, such as ESChat on AWS commercial and GovCloud15 | TASSTA keeps data on local storage;12 Privox states that voice, messages and locations stay in your infrastructure20 |
| Features | The full set | Zello Enterprise Server has no transcription, translation or single sign-on;9 GroupTalk On Premise has no Active Directory user handling and no full-duplex private calls with live video13 |
| Size | Set by the vendor | POCSTARS MiniServer 2.0 serves 50 to 200 users;19 WAVE PTX On Prem serves 200 to 100,000 or more11 |
| Price | GroupTalk Cloud: from EUR 8 per user a month, no platform fee | GroupTalk On Premise: from EUR 8 per user a month plus a platform cost on request13 |
| Failover | The vendor's job | WalkieFleet replicates a master server to a backup that takes over clients;3 WAVE PTX On Prem includes software for a 1+Geo redundant pair11 |
Which PoC platforms offer an own-server option?
These platforms state that the server can run on your own hardware or in your private cloud. The list is alphabetical and shows each vendor's own description of the option. The software hub has the same filter, "Runs on your own server", across all platforms in our database.
| Platform | Own-server option, as the vendor states it |
|---|---|
| ESChat | Hosted in your own private cloud, or on-premise on your own server hardware15 |
| GroupTalk | On-premises: a server placed in a local IT environment, next to Cloud and Private Cloud13 |
| InterTalk Enlite (dispatch platform) | Deployed fully in the cloud, air-gapped on-premises or as a hybrid of both16 |
| LINX PTT | Subscription cloud, and on-premise or private solutions17 |
| Motorola WAVE PTX | WAVE PTX On Prem, installed in the customer's secure IT network11 |
| PoC Me | French reseller of WalkieFleet; sells the software for customers who handle hosting, configuration and maintenance themselves18 |
| POCSTARS | MiniServer 2.0, a compact on-premise server for small and medium sites19 |
| Privox | The server can sit on the customer's side, or Privox hosts it20 |
| RealPTT | Agents create independent servers for customers who supply a server and an IP address21 |
| TASSTA | Inside your own IT, in a private data center or on dedicated servers, or in TASSTA Cloud12 |
| Voxer | Enterprise plan: dedicated cloud or on-premise hosted solutions, quoted22 |
| WalkieFleet | Server software for Windows or Linux that you or a partner installs47 |
| Zello Work | Zello Enterprise Server, on your own server in your own environment9 |
What does an own PoC server need to run?
Requirements come from the vendor. WalkieFleet recommends a Windows 10 or Windows Server 2008 R2 or newer machine with a Core i5, 8 GB of RAM and 500 GB of disk, plus a Linux build. WAVE PTX On Prem and POCSTARS MiniServer are sized by users: 200 to 100,000 and 50 to 200.471119
WalkieFleet publishes the most detail:
| Item | Requirement |
|---|---|
| Windows | Windows 10 or higher, or Windows Server 2008 R2 or higher; 64-bit installer47 |
| Hardware (recommended) | Core i5, 8 GB RAM, 500 GB disk4 |
| Database on Windows | SQL Express 2014 installed by default, or a corporate Microsoft SQL Server4 |
| Linux | Debian package for amd64 (.deb); PostgreSQL by default or MS SQL Server; the database account needs superuser rights to create the databases67 |
| Network | Wired connection, a fixed LAN address or DHCP reservation, and for production a fixed WAN IP with port forwarding on the router8 |
The other own-server products describe their scope instead of a hardware list:
- WAVE PTX On Prem suits closed or isolated networks and private wireless networks. The standard deployment includes software for a 1+Geo redundant server configuration, expandable to 1+1+Geo.11
- POCSTARS MiniServer 2.0 targets hotels, campuses and facility sites with 50 to 200 users.19
- Zello Enterprise Server runs on your intranet without internet. Dispatch analytics and Apple's push-to-talk framework still need an internet connection.9
Which ports does a PoC server use?
Ports depend on the product. WalkieFleet uses TCP 9999 for its service and, for each network, a TCP command port plus UDP voice and video ports, starting at 10000 and 10001. Every port must be reachable from the clients, so the router and firewall in front of the server need matching rules.58
| Port | Protocol | Default | Purpose |
|---|---|---|---|
| Service port | TCP | 9999 | Dispatcher, Server Manager and master-to-backup link5 |
| Command port | TCP | 10000 | Mobile clients5 |
| Voice port | UDP | 10000 | Voice stream5 |
| Video port | UDP | 10001 | Video stream5 |
| WebSocket port | TCP | none | Third-party applications5 |
Each network on the server uses three or four ports, and the defaults shown are for the first network.5 Antivirus software and corporate firewalls can block these ports, so check them when clients cannot connect.8
How much bandwidth does a PoC server need per user?
A talker needs about 12 to 56 kbit/s, depending on the app and codec, and an idle user almost nothing. The server's load grows with the listeners, because it sends one copy of the voice to each member. Ten listeners on a 16 kbit/s call add up to 160 kbit/s leaving the server.2410
| Basis | Rate |
|---|---|
| WalkieFleet voice | 16 kbit/s narrow band, 24 wide band, 32 super wide band, 56 full band; video PTT 512 kbit/s4 |
| Zello | 12 kbit/s on 2G to 45 kbit/s with both users on Wi-Fi; 20 kB an hour idle; 70 to 100 MB a month on average10 |
| Microsoft Teams Walkie Talkie | About 20 kbit/s sending or receiving23 |
The sum for the server is the number of active calls times the listeners in each, times the voice rate. Use the PoC data usage calculator for monthly data per radio, and the RoIP bandwidth calculator for kbit/s per channel with IP headers.
Questions
What does PoC server mean?
A PoC server is the central software of a push-to-talk over cellular system. It registers clients, manages talk groups, grants the floor and relays voice to the group.12
Is a PoC server a piece of hardware?
No. It is software that runs on a machine you choose or on the vendor's cloud. WalkieFleet, for example, installs on a Windows or Linux computer.47
Can I run Zello on my own server?
Yes, with Zello Enterprise Server. It runs in your environment on a local intranet without internet, and it has no transcription, translation or single sign-on.9
Does a PoC server need a public IP address?
For clients outside your network, yes. WalkieFleet asks for a fixed WAN IP and port forwarding in production, and a fixed LAN address or DHCP reservation for the server itself.8
Sources
- OMA Push to talk over Cellular (PoC) architecture, version 2.1 (2 August 2011) · Open Mobile Alliance
- WalkieFleet features · Walkie Labs
- WalkieFleet system requirements · Walkie Labs
- Ports used by WalkieFleet Server · Walkie Labs
- WalkieFleet Server installation, Linux version · Walkie Labs
- WalkieFleet downloads and release dates · Walkie Labs
- WalkieFleet Server deployment recommendations · Walkie Labs
- Zello Enterprise Server (ZES) overview · Zello Work Help Center
- How much data bandwidth does the app use? · Zello Work Help Center
Show all 23 sources
- WAVE PTX On Prem data sheet · Motorola Solutions
- Deployment: on-premise and cloud · TASSTA
- GroupTalk PTT service: questions and answers · GroupTalk
- Service hosting options · ESChat
- InterTalk Enlite · InterTalk Systems
- LINX PTT on the App Store · Apple
- POCSTARS launches MiniServer 2.0 for small-site push-to-talk deployments (20 February 2026) · Critical Communications Review
- RealPTT system main features (feature document, 2026-05-07) · Shenzhen Corget Technology
- Voxer plans and pricing · Voxer
- Manage the Walkie Talkie app in Microsoft Teams · Microsoft
