SIP & ISDN Trunking

Flexible voice connectivity for modern and legacy systems.

Voice trunking solutions that support reliable call routing and gradual modernisation.

SIP and ISDN trunking provide the connection between internal phone systems and the wider public telephone network. While many organisations are moving away from ISDN, both technologies still play a role during periods of transition.

Greenfire Solutions helps organisations design trunking solutions that balance reliability with future readiness. This includes supporting existing ISDN services while planning and implementing SIP-based alternatives that offer greater flexibility and cost efficiency.

Our focus is on call quality, resilience, and smooth migration paths — ensuring voice connectivity remains dependable as infrastructure evolves.


SIP & ISDN Trunking