Network requirements - VoIP

The secure calls with PrivateGSM travel through a network of IP connection, typically the Internet.

The network used by PrivateGSM are provided by the mobile operator (GPRS, EDGE, UMTS) or WiFi which is normally connected to the Internet (ADSL, fiber).

Mobile internet connections

PrivateGSM mobility requires a complete Internet connection.
PrivateGSM can not work with networks WAP, MMS or exclusively WEB.
It  requires a full internet connection, that you can tipically require to your telephone operators asking to be able to establish a VPN (virtual private networks) based on UDP.

Some telephone companies place limitations on the use of explicit VoIP communication services and offer specific plans to use these technologies.
PrivateGSM Professional obfuscates all traffic in order to overcome any locks held by operators and / or non-democratic countries, but this could involve a breach of contractual terms with the provider.
You should check with your operator if the current pricing plan allows the use of VoIP technologies.

Calling plans

To receive calls safe PrivateGSM requires an open connection to the Internet: it is therefore important to activate a calling plan that provides the ability to stay connected all the time necessary to receive and make calls safe (eg: 24 hours / 7).
The costs depend on the rate plan agreed with your telephone service provider and a not careful management of pricing conditions could lead to exorbitant costs.

We recommend that you contact your operator to agree a flat rate allowing a continuous connection.
In general, the tariff plans of mobile internet connection can be divided into two main types:

• A limitation of traffic: you pay according to the data traffic during the connection. On average, PrivateGSM exchanges data packets for a total of 2MB per month. This figure is calculated by assuming the bandwidth between the media and 100k/minute 200k/minute. So, 1MB of Internet traffic corresponds to a minimum of 5 minutes up to a maximum of 10 minutes.
• A time limit: you pay over the duration of the connection. These plans are disadvantageous and not suggested when using PrivateGSM. If you need to use PrivateGSM abroad, is even more important to get a data plan to connect to the Internet without high costs.

Bandwidth

The bandwidth requirements to make secure calls are very low, about 1 Kbyte / s for Nokia and iPhone platforms and about 2.1Kbyte / s for the BlackBerry platform.

Bandwidth consumption to keep the connection always online with the phone server is about 1Mbyte/month.
The consumption of bandwidth during the call is 100Kbyte/min and 200Kbyte/min according to the phone platform involved.

Quality of communication

It 's very important to consider the quality of a VoIP communication, since you can have difference perfomances.

The characteristics of the communication channels that impact on PrivateGSM are:

• Latency: this represents the perceived delay in the communication between caller and callee
• Packet Loss: determines the presence of small audio dropouts during the call
• Bandwidth: determines whether or not you can make a call with an acceptable quality
• Firewall: the presence of filters may prevent PrivateGSM connection to the server and / or to make voice calls

Firewall and communication ports

It may be necessary in some contexts explicitly enable traffic PrivateGSM corporate firewall.

PrivateGSM Enterprise uses the communications protocols that should be able to pass between client and PBX, thus requiring openings on your firewall:

• SIP / TLS uses TCP connections on port 5061 (or any other port configured)
• SRTP uses UDP connections on a port range between 4000 and 20000 (or any other range configured)