FAQs


 

 

 

 

 

What is VoIP?

VoIP (Voice over Internet Protocol) converts the voice signal from a telephone into a digital signal that can travel across any internet-based protocol and then convert it back to a voice signal when it reaches the recipient telephone.

 

 

 

What is IP Telephony (Internet Protocol Telephony)?

IP telephone systems initiate, process, and receive voice communications via Internet Protocol (IP) networks. These IP networks may be public IP systems (e.g. the Internet), private data systems (e.g. LAN based), or a mix of public and private systems.

 

 

 

What is an IP Telephone?

An IP telephone is specifically designed to communicate through the Internet without the need for a voice gateway. Internet telephones contain embedded software that allows them to initiate and receive calls through the Internet using standard protocols such as H.323 or SIP.

 

 

 

What is DPNSS?

DPNSS, or Digital Private Networking Signalling System, is a British signalling protocol developed to network two or more PBXs together and to allow the features and services of the PBXs to work over the network. As such, DPNSS is classed as a private networking protocol.

 

 

 

What is the difference between QSIG and Q.931?

Q.931 is an access protocol; it is designed to work between the PSTN (Public Telephone System) and a PBX (Private Telephone System). It does not support the same features and services as a private networking protocol. QSIG is a private networking protocol and will support many of the same features and services as DPNSS

 

 

 

What is H.323?

H.323 is a standard that specifies the components, protocols and procedures that provide multimedia communications services- real time audio, video, and data communications- over packet networks, including Internet Protocol (IP)-based networks. H.323 is part of a family of ITU-T recommendations called H.32x that provides multimedia communication services over a variety of networks.

 

 

 

What are Centralised Operator Services?

Centralised Operator Services allow an operator at one PBX to deal with calls from remote PBXs in the network, with no loss of functionality relative to a notional operator stationed at the remote PBX.

 

 

 

What is the difference between ETSI ISDN and EURO ISDN?

Very little, they are both based on the Q.931 specification but ETSI ISDN is an older protocol and does not have some of the services available to EURO ISDN.