SIP Trunks

SIP trunks are a cost effective way of connecting from your premises to the public switched telephone network (PSTN). They provide lower voice access costs when integrated into a data network and lower call costs than traditional phone lines. Most new telephone systems support sip trunking natively however you can also connect an ISDN (onramp 10,20,30) to SIP gateway to enable legacy PBX's to support VoIP.

Common ISDN features are supported on the Anticlockwise SIP Trunking Network

What is SIP?

SIP stands for Session Initiation Protocol and is the basis for next generation communication networks. SIP allows voice, video calling, presence and messaging to be transmitted and controlled across an IP network using a single protocol. SIP has emerged as the standard way to communicate between Voice over IP networks.

Hosted PBX

Hosted PBX or cloud based PBX solutions are a great way to avoid large capital investments in hardware that will be quickly outdated. Combined with a carefully managed and quality data network, a hosted solution is great for supporting multiple sites without investing in a new PBX at each location.

Support of the phone system and access to new features as they are released are also covered by a standard monthly fee. Our hosted PBX solution utilises the SIP protocol which means you are not coupled to any particular phone handset vendor and can utilise any SIP capable handset with our hosted phone solutions.

Key Hosted Features:

Number Hosting and Porting

The Anticlockwise VoIP network supports number porting from all major Australian carriers. This includes 1300/13/1800 numbers, standard PSTN numbers, BRI and ISDN (ONRAMP 10/20/30) services.


VoIP is not always the best solution for every customer. For this reason Anticlockwise also offers a full suite of PSTN & ISDN solutions.

Hybrid Voice Networks

Combining on-site solutions with a hosted solution

Sometimes the best solution is a mix of different technologies. Enhancing an existing onsite PBX at your main office with a voip gateway and extending to branch offices with a hosted solution allows you to preserve your existing PBX investment and deploy a cost effective solution for new locations. You will also get the added benefit of free calls between all of your offices.

Integrating older voice technology

Managing voice deployments containing a mix of old and new technology requires a hybrid approach to ensure the existing investment in technology is not wasted.