0. Introduction

Glossary

PBX

A private branch exchange (PBX) is a telephone exchange that serves a particular business or office, as opposed to one that a common carrier or telephone company operates for many businesses or for the general public. 

PBXs make connections among the internal telephones of a private organization—usually a business—and also connect them to the public switched telephone network (PSTN) via trunk lines.

Trunk

A trunk line is a circuit connecting telephone switchboards (or other switching equipment), as distinguished from local loop circuit which extends from telephone exchange switching equipment to individual telephones or information origination/termination equipment.

When dealing with a private branch exchange (PBX), trunk lines are the phone lines coming into the PBX from the telephone provider. This differentiates these incoming lines from extension lines that connect the PBX to (usually) individual phone sets. 

Extensions 

A telephone extension is an internal telephone line attached to a Private branch exchange (PBX). The PBX operates much as a community switchboard does for a geographic telephone numbering plan and allows multiple lines inside the office to connect without each phone requiring a separate outside line. In these systems, a dialer usually has to dial a number to tell the PBX to connect with a landline to dial an external number. Within the PBX, the user merely dials the extension number of the person. Each phone line may be extended up to a fixed maximum.  

Secure Call

A Secure Call is a voice connection which can't be wiretapped and it runs over Voice Over IP (VoIP) communication protocol.

PrivateServer

PrivateServer  is the PBX committed to perform Secure Calls both end to end and end to site. It differs from a standard PBX for exposing just the Secure Call service to VoIP  PrivateWave  clients and can be connected to a standard PBX via SIP Trunks if configured accordingly.

PrivateWave

PrivateWave  is the VoIP client for Secure Calls connections. It has to be used along with  PrivateServer .

Jitter 

In VoIP systems audio signal is split into multiple packets, which are sent over network. Due to network equipment behavior, packets flow is never regular and constant. Especially on mobile/radio networks packets are delivered in bursts, leading to irregular and variable latency. Jitter is the variation in latency as measured in the variability over time of the packet latency across a network. 

Automatic Activation 

The Automatic Activation is the way of create new users automatically without any need they interact with anybody. As from user's side the procedure is that he/she gets first an invite SMS or E-Mail useful to download the application  PrivateWave  and then a configuration SMS or E-Mail which provides automatic configuration of the client itself. All the user has to do is to follow the links into both the Texts/E-mails and  PrivateWave  would go automatically on line.

Provisioning

 The Provisioning is the configuration needed for delivering both for the  PrivateWave  application and its configuration and nowadays it's used by the Automatic Activation only. 

Presence

The Presence is how we call the user's status, also known as the user's reachability. By checking an user's Presence it is possible to know if a he/she is on line and can receive a secure call before trying to.

Audio Messaging

The Audio Messaging is the means used by  PrivateWave  for communicating to an user about the failed calls. You have several messages that can be spoken and each of them can be localised in English, French, Italian, Spanish and German.

Secure Message

Secure Message is a text message that can be sent and received only by using  PrivateWave  and that shares the same communication infrastructure of Secure Call. The maximum length of each message is 160 character.

Call Roaming

Call Roaming is specific configuration set up by default on both  PrivateServer  and  PrivateWave . It let any call to continue even if one network change event occur (e.g: wi-fi network got lost in favour of 3g data mobile one). During network change itself the call is muted but as soon as any connection is again available, then voice stream is back streaming. Call roaming is subject to Strictrtp and Rtp timeout options in  PrivateServer .