VoIP gateways are special types of media gateways that bridge traditional telephony networks to modern-day voice over ip analog FXO & FXS, digital BRI & PRI telephony networks. There are several brands that have standard devices each with one telephone communication port and one ethernet communication port. Deployment of a voip networks involves a very detailed analysis based on the network usability, scalability, & troubleshooting. Hence it is very important to choose the right equipment and a tailor-made solution for the particular network in question. Nowadays, the list of vendors that sell voip gateways are innumerable and the list is growing by the day. However, there are a few popular brands like Dinstar, Portech, Hypermedia, & Grandstream, that have stood the test of time.
One of the oldest vendors is Portech. Based in Taiwan & being in this business since more than thirty years, Portech claims to be the leader in voip products. It has compatibility with most international frequencies including CDMA, EDGE, 3G/UMTS, QuadBand GSM. It supports a full 31 channel E1 bank and comes with a variety of ports so that clients can choose the one that is most cost-effective for them. It gives users the exciting feature of Remote SIM on a single port. Extending its features to the limit, it has an Asterisk GSM Card support that can be used to easily plug-in a prebuilt Asterisk GSM bridging feature to one of the 2 supported PCI slots. Keeping in view the tremendous growth of the internet voice client, Skype, Portech also has a Skype gateway that enables users to establish a ‘SkyTrunk’ that offers 100% free voice calls between the IP PBX and Skype!
A close competitor is Dinstar emerges as an industry leading manufacturer of a variety of VoIP products, having involved in the VoIP business for around 10 years, it has grown to occupy a huge majority of ISP’s world over, mainly owing to the professional R&D team seasoned in the fields of telecom networks and data communication. The Dinstar QuadBand GSM-VoIP bridging gateways allow any SIP/VoIP line to be connected directly to the GSM network, which can considerably lower the cost of mobile originated traffic. Like, Hypermedia, it also supports configuration via web portal, SMPP protocol, and asterisk gateway support, but it extends all its features by providing dramatic compatibility with not only Asterisk, but with most of the modern day PBX alternatives and extensions of Asterisk, like Freeswitch, Elastix and Trixbox.
The VoIP Gateways from Hypermedia are designed for interconnecting a wide selection of analog and digital IP signaling protocols. It supports few SIP audio codecs, and advanced low cost routing to significantly cut down on GSM (national as well as international) roaming charges. Supporting 72 SIP channels at a time, it has extensive compatibility with Asterisk, Cisco, Avaya and other major vendors. With its intelligent PSTN compatibility, helps further minimize landline costs by integrating PRI cards. It has an easily configurable web based management portal, a local serial port, and optional features of redundant power supply, & SMPP communication protocol functionality.
Last but not the least; Grandstream. Having its scope set to SIP VoIP products, Grandstream is a leader in its focused but limited area of production. They offer many feature-laden sip clients that address a variety of consumer class. Having compatibility with analog products too, Grandstream comes in as a standard choice when dealing with conventional telephony products. However, in case of an error or troubleshooting scenario, it doesn’t give provide any logs, traces or dump information to analyze the traffic and parameters needed for resolving connectivity issues.