Non-stop IP Performance
Silicon Valley-based Aspen Networks (www.aspen-networks. com) is another example of an SMB VoIP gateway that solves the network address translation (NAT)/firewall traversal problem with a built-in SIP proxy. In addition, the Aspen’s 365-VoIP utilizes multiple active Internet access links for built-in fault tolerance, optimal bandwidth usage, and QoS. The solution continuously monitors the status and health of all WAN links to and from the customer premise network edge. And the technology detects outages or service degradations in milliseconds and maintains VoIP sessions and quality without dropping calls by switching traffic to alternate paths.

The 365-VoIP is designed for the hosted VoIP market and is sold through service providers that deliver enterprise-like IP PBX functionality as an easy-to-deploy, affordable monthly service. By outsourcing all of the management aspects of IP-based telephony, SMBs can save costs and eliminate the worry and headaches associated with voice infrastructure management. The solution also enables service providers to implement SIP survivability and insulate its service delivery and QoS from common Internet outages and other transient problems.

IAD Enables Multimedia LAN SMBs
Intertex (www.intertex.se) and Ingate (www.ingate.com) are sister companies located in Sweden. Ingate targets enterprises, and its products feature SIParator technology. Traditional firewalls are not SIP-capable, and therefore they block SIP traffic, including VoIP. However, the company solves the NAT/firewall problem using a built-in SIP proxy to control the NAT and firewall engine. “SIParator,” the product’s designation, allows companies to keep their existing firewall; i.e., it enables SIP-based communications to traverse the firewall while working in tandem with current security solutions.

Intertex markets firewall/routers and IADs to the residential and SMB sectors, and they have a comprehensive range, but at VON Europe in Stockholm the company introduced an innovative IAD that enables a so-called multimedia LAN. Home networks normally start with a wireless access point and some kind of IAD, so there’s a NAT/firewall issue, particularly when running VoIP. Add IPTV, which comes in on a separate cable and has no connectivity to the PCs, and you have a second LAN.

In some cases you might have a separate LAN for VoIP with no connectivity to the other LANs. On it’s own, you have a lot of wires and the inability of using more than one service on a particular terminal. There may also be further complexities such as two or more NAT/firewall combinations on top of each other. The multimedia LAN brings it all together, solving the NAT/firewall traversal issues and enabling all the terminals to access the relevant services.

The IAD handles IPTV/VoD, IMS/VoIP, Internet, and ADSL/ VLAN. It’s also a wireless access point and an ATA, so you retain your wireless LAN and can do VoIP from your PSTN devices. There’s no battery draining of WiFi mobile phones and PDAs. Traditional methods of SIP NAT-traversal try to keep paths open by frequent “wake-up calls,” and that inhibits the sleep mode. But best of all, a single cable allows you to hook up everything else–PCs, SIP phones, and the set-top box.

Thus, all services on different permanent virtual circuits (PVCs) are made available to all terminals on a single LAN. And there is full, SIP-based, live IP communications support.