VoIP expert settings
Easybell supports SIP in accordance with RFC3261 (SIP 2.0). Encrypted connections via TLS and sRTP as well as modern codecs such as G.722 are also supported.
The automatic default settings are sufficient for most end devices. The following reference values will help you with specific requirements or problems.
SIP settings
SIP server / registrar
The registrar depends on the product to be set up.
All registrars support both DNS-SRV and encrypted telephony (TLS/SRTP).
| Product | Registrar |
|---|---|
| SIP Trunk / VoIP | voip.easybell.de |
| Cloud Telefonanlage | pbx.easybell.de |
Ports & protocols
| Application | unencrypted | encrypted |
|---|---|---|
| Phone numbers & number blocks | 5060 (UDP or TCP) | 5061 (TLS) |
| Cloud telephone system | 5060 (UDP or TCP) | 5061 (TLS) |
Encryption
Our registrars support the encryption of both signaling (SIP) and media data (RTP) according to current standards - via TLS (Transport Layer Security) and SRTP (Secure Real-Time Transport Protocol).
Requirements:
- The end device must support TLS and SRTP.
- Both protocols must be set up in the device.
Important: The Easybell app does not currently support encryption.
Further information can be found in our instructions for the respective devices or telephone systems, as well as in the general article "How to encrypt your telephony".
Advanced SIP settings
The following reference settings provide the best results for most devices. However, different settings may work better for your installation.
The designation may differ for your device. If in doubt, please contact the manufacturer.
| STUN server | Deactivate |
| Outbound proxy mode | Automatic |
| Expired Timer | 3600 (Min. 600) |
| SIP Max Forwards | 70 |
Audio & Codecs
The following reference settings provide the best results for most devices. However, different settings may work better for your installation.
The designation may differ for your device. If in doubt, please contact the manufacturer.
| Long SIP Contact | RFC3840 recommended |
| DTMF via SIP INFO | Deactivate |
| DTMF | Outband (RFC2833) or Inband |
| Jitter Buffer (JB Min) | 20-30 The value should only be changed in urgent cases and should always be based on the line. |
Codecs
We recommend using the following codec sequence:
| 1. | G.722 |
| 2. | G.711A (PCMA) |
| 3. | G.711U (PCMU) |
Note on emergency calls: The G.711A codec must be configured.
G.711A is established as the minimum standard in Europe and is essential for emergency call functionality.
Network settings
RTP Portrange
If you want to ensure proper transmission of the RTP voice stream for all our voice services, you can release ports 10,000 to 50,000 (UDP),
If you want to release a narrower range, the following table will help you:
| Application | Portrange (UDP) |
|---|---|
| Phone numbers, number blocks & virtual extensions | 20,000 - 50,000 |
| Cloud telephone system end devices | 10,000 - 50,000 |
| Easybell app | 10,000 - 20,000 |
Ports for additional services
- Easybell app: 4998 (UDP) & 4998, 5000, 4210, 4280 (TCP)
- Cloud telephone system (automatic configuration of end devices (ACS)): 443 (HTTPS)
- Alternative port for phone numbers (blocks): Some routers affect port 5060, alternatively port 5064 can be used for UDP or TCP. This does not work with the cloud telephone system!
Notes on infrastructure
| Load balancing and multi-WAN functions | Deactivate | For security reasons, RTP and SIP packets should always be sent from the same public IP address. |
| SIP-ALG in the router | Deactivate | |
| RTCP | Enable | RTCP is supported by Easybell. |
| RTP Keepalive | Activate | Keepalive messages are activated and prevent timeouts during longer periods of inactivity. |
Special applications
Easybell app
If there are problems with calls via the Easybell app, please check whether the following resources are enabled in the router or firewall:
- TCP ports: 4998, 5000, 4210, 4280
- UDP ports: 4998, 10000-20000
- Hosts: webrtc.easybell.de, webrtc2.easybell.de
Fax devices
Fax-over-IP is technically demanding. Good results were achieved with the following settings:
- Baud rate: 9600
- ECM (Error Correction Mode): activated
- High Speed Fax (Super G3/V.34): deactivated
General information on fax transmission via VoIP can be found in our detailed article on the subject of fax.
