SIP is the protocol of choice for telephony, conferencing and other communications sessions on the Internet.
Reduce Costs with SIP Trunks
A SIP Trunk can connect your company’s SIP-enabled devices, such as an IP-PBX or IP phones, to the outside world without the need for gateways to convert TDM traffic to VoIP. With SIP trunks, your company saves on multiple PSTN circuits and the capital and operating costs of voice gateways and other PSTN interface hardware.
Use IAX Trunks for Asterisk-to-Asterisk Communications
An IAX trunk (Inter-Asterisk Exchange) is the means to interconnect Asterisk-based servers. Because it uses a single port for both channel signaling and RTP (real-time protocol) streams, it has a distinct advantage over SIP trunks when internetworking with NAT and firewalls. An IAX trunk is also more bandwidth-efficient than a SIP trunk because it has much lower network overhead. If your company has an Asterisk-based PBX for local or national calls - or if you are a small Asterisk-based VoIP service provider - we can quickly connect you to DOW Networks’ Asterisk platforms, providing you with high quality call terminations, worldwide, at very low rates.

SIP and IAX trunks are pure IP connections that can offer your company significant cost savings by eliminating the need for local PSTN gateways, costly ISDN BRIs (Basic Rate Interfaces) or PRIs (Primary Rate Interfaces). Get SIP and IAX trunks from DOW Networks:
- Realize the efficiency and cost benefits of VoIP
- Enjoy low international rates
- Get 24x7 technical support
We also can meet your SIP phone requirements with softphones or Polycom IP phones.






