DEFINING AN INTEGRATED ACCESS

device has never been easy, and the technological evolution to IP networking hasnt made it any easier. Most will agree an IAD is gear that links premises communication devices to the network. Beyond that, all bets are off.

For the purposes of this article, then, an IAD is a device used to connect multiple phones and/or data devices to an access network. In former days, when most small businesses had key systems or possibly small PBXs, an IAD might link that PBX to a T1 line or to multiple analog lines (for a very small office). The PBX connected to the IAD using a connection called a DS1 connection and the IAD also could provide interfaces to ordinary phones so they could use the T1 directly.

By 2004, CLECs had moved heavily into sales of integrated T1s, in part, because the ability to combine voice with data and to control voice bandwidth dynamically was appealing to small business.

The CLECs, in 2004 or 2005, took the small business market completely away from ILECs on that basis, says Keith Nissen, a senior analyst for In-Stat. These IADs were being put in to connect customer premises equipment to these integrated T1s.

Now integrated T1s, which have been using the MGCP protocol, are starting to migrate to SIP, so-called SIP trunking. With SIP trunking, traffic can signal directly to a hosted SIP service in the network to deliver advanced services, even to legacy equipment. Chris Thompson, product manager, Enterprise Networks Division for ADTRAN Inc., says he is seeing providers offering TDM T1s and those offering integrated T1s using MGCP moving to SIP. ADTRANs first SIP products, the 900 series, debuted in 2005 and span both the IP and TDM worlds. On the customer side, they have analog ports to legacy devices as well as SIP capabilities, which include the ability to act as a backup SIP registrar for devices on premises. This means, if a T1 goes down, IP phones still can call out using analog lines.

Many new products support legacy CPE, such as TDM PBXs and key systems, but also anticipate customers might have IP phones on premises or be interested in migrating to that equipment in the near future. These IADs are IP and VoIP toward the network, but toward the user, they present a standard PRI interface into the PBX, says Ed Harper, director of product management at Telco Systems, a company of BATM Advanced Communications Ltd.

At GLOBALCOMM this month, Telco Systems is debuting the Access 500, which straddles TDM and IP. It has a PRI link for a traditional PBX and includes four FXS lines for fax machines. It also includes Ethernet ports for LAN connections and the ability to do one or two T1s on trunk side. All voice signaling is SIP, and one of the Ethernet ports can be configured to be an uplink to another location.

Edgewater Networks Inc. also is offering a new product, Edgemarc Enterprise, which facilitates SIP trunking. Sitting between the T1 trunk and the IAD, the product acts as a voiceaware NAT firewall. It provides QoS by recognizing and prioritizing SIP packets. It is centered around how to make it easy to connect to a SIP trunk in the core and how to make it easy to have high-quality conversations, says Dave Martin, vice president of products, Edgewater Networks.

In recent years, access device makers have begun to add features, such as firewalls, routing and other security functions. So a device that used to be just interconnection to a T1 line with a bunch of analog interfaces is now a router, a firewall, Ethernet connections, and, in addition to these, analog ports, says analyst Nissen.

Access network choices have changed, too. Now, it can be T1 in or direct Ethernet or a DSL connection or an E1 connection, Nissen adds. With this new constellation of functions, he no longer calls these devices IADs, preferring multiservice gateways, a term favored by many vendors.

Converged Access Inc., for example, has embraced the concept of the do-it-all IAD. The companys CAP 1000, introduced earlier this year, is designed to be drop-shipped to branch offices of large enterprises, as well as small businesses. An IT manager can establish one set of policies and distribute that automatically to thousands of IP end devices at remote locations. The CAP 1000 includes a router and firewall, and support for remote monitoring. It supports DSL or cable access as well as T1. It is a single device at the customer premises to provide the required suite needed to do VoIP and SIP trunking, says Manickam Sridhar, CTO, Converged Access. The product can do file transfers and IP calling with SIP phones, protecting bandwidth for the voice calls; provides analog ports for legacy equipment, such as fax machines; converts traffic to SIP; and provides reports on voice quality.

But even more functionality may be just around the corner. A new product segment will be hitting the market in 2006 and even more in 2007. This will be a product that gets put on premises and wont need the old analog interfaces that an IAD had but will service all the functions that a branch office or small business needs, says Nissen. Service providers, he says, can bundle transport and these office-in-a-box products, which he calls business gateways.