Compared to ISDN, SIP Trunking is cheaper on a per channel basis, more flexible in terms of what telephone numbers you can have and where you can have them, is quicker to install and offers a very robust business continuity service that ensures your business never loses calls.
SIP Trunking connects your PBX to our network enabling full PSTN breakout on the public telephone network. Connection from your site or sites to our network is via an IP connection, for example broadband or Ethernet, and is delivered as an end-to-end service with an availability guarantee, voice channel guarantees, and voice quality of service assurances.