ISDNConventional Office Phones Systems are made up of handsets which are wired into a physical PBX that handles all logic and function of the system. The PBX is connected to the PSTN via ISDN lines provided by BT physically cabled into the building for the exclusive use of voice calls. Internet is delivered over an independent infrastructure.

Conventional ISDN

PBXISDN

Socket

ISDN Lines

PSTN

RouterInternets

SIPA SIP Trunk is a virtual ISDN line connecting the PBX to a carrier. The SIP Trunk translates the ISDN signaling into network packets to send over the internet. SIP makes ISDN and it’s physical infrastructure obsolete.

● Increased channel capacity● Disaster Recovery● More Complex Routing Options

● Opex Savings● More Flexible Contract Terms● Short Setup Lead Time

ISDN LinesPBX

ISDN Socket

PSTN

RouterInternets

SIP Signaling

SIP

HOSTEDHosted VoIP is the entire telecoms infrastructure including both PBX and SIP Trunk virtualized in the cloud. Hosted often utilises the existing internet and network infrastructure. Hosted does not require the end user to have their own PBX which is more cost effective from a capex or hardware installation point of view. Both SIP and Hosted can benefit from network features similar to ISDN.

● Same advantages as SIP Trunks, plus● Many additional features for both inbound

and outbound calling and call handling● In-house and 3rd party Integrations

● Ability to expand functionality further● New features added as can be imagined● Vastly reduced CAPEX

PBXISDN

Socket

ISDN Lines

PSTN

RouterInternets

SIP Signaling

Hosted