The beta version of the Nautica 250 I tested offers a solid mix of features for SOHO environments. It performs bridging and IPX routing and supports international POTS services. The router supports two POTS lines (particularly valuable in a home office), Ethernet bridging, IP and IPX routing, and IP NAT (Network Address Translation). In the lab, its management interface allowed granular control of routing and telephony functions.

Packaged in a shell-shaped box, the Nautica 250 is stylish, small and unobtrusive. Its lone LED signals if the device is booting (flashing red and green), idle (solid green) or in use (flashing green).

Although its support for two POTS lines makes it suitable for home offices, the Nautica 250's advanced routing features make it more useful as a small-office router. On the telephony side, it supports advanced voice features, such as distinctive rings and selective data-call interruption based on MSN (Multi-Subscriber Numbering--a service provided by local telephone companies). During testing, the Nautica 250 adroitly handled incoming voice calls by dropping on-demand data calls.

I ran several performance tests on the Nautica 250, and found that it could handle the full capacity of a Multilink PPP dual-ISDN connection--approximately 14 KB per second of data throughput, accounting for TCP/IP protocol overhead.

Installation and Management Setup was relatively simple. While a novice may never say an ISDN router is easy to configure, Nortel provides a helpful wizard-based installation utility. Like most SOHO routers, the Nautica 250's installation process begins with a Windows configuration utility. From there, the Nautica Wizard's Installation Assistant poses a few simple questions to determine how to provision the device.

The Nautica 250 includes auto-SPID (Service Profile ID) detection--a boon for newcomers to ISDN. However, this capability means specifying a different switch type (called "autosense"), and then rebooting the router for the new SPIDs to take effect. The router also offers DHCP support, but you must manually configure address ranges before clients can lease an IP address. So when configuring the device, your workstation needs a manually configured IP address in the 192.168.1.0/24 subnet. According to the vendor, the lack of initial DHCP was by design--it makes no assumptions about your local configurations. This is a prudent assumption, particularly if the router is installed on a network that already has a DHCP server. However, it may confuse home-office users who expect everything to work out of the box.

The only other required configuration was the ISDN numbering (area code, line numbers and SPIDs--if not using SPID autodetection), an ISP number and log-in credentials. Autodialing worked flawlessly, and more important, behaved logically. However, the unit did not supply default settings for the dynamic allocation of a second "B" channel based on usage. I set it to make a second call when the activity exceeded 65 percent utilization for 10 seconds, and dropped the call when utilization fell below 10 percent for 10 seconds (recommended by Nortel). Once set, bandwidth on demand worked well. According to Nortel, automatically enabling this feature when an ISP doesn't support multilink PPP can wreak havoc, possibly causing the second B channel continuously to attempt to connect and fail to log in.

In addition to the Nautica Wizard, Nortel includes two monitoring tools: a "log watcher" utility and Nautica Watch, a graphical utility that displays bandwidth and line usage. Both SNMP-based utilities provide a detailed look at the router's behavior. Using two bar graphs to represent usage on each B channel, the Nautica Watch utility made up for the router's lack of separate LEDs to indicate channel usage. It also shows incoming Caller ID numbers and the numbers dialed for outgoing calls. Coupled with user-selectable logging levels on virtually every function in the device, the Nautica Watch utility made this router easier to diagnose than any I've seen.

The Nautica 250 also includes simple yet very valuable tools for diagnosing autodialing difficulties. The Nautica Wizard includes alarms you can set for excessive numbers of autodials, as well as for limiting call length. It also offers an option to display an autodial history log and the pertinent IP protocol. The culprit, in my case, was my laptop's WINS (Windows Internet Name Service) client, which periodically registered itself with our corporate WINS server, resulting in scores of calls throughout the night. To address this problem, the Nautica 250 includes a WINS proxy server.

While the Nautica 250 has IP filters to block specific protocols and conversations, I'd like to see an optional autocall-blocking filter, which would enable NetBIOS session traffic if a call is connected, but wouldn't initiate a call for a NetBIOS request. Windows networking tends to be quite chatty--especially when talking to remote servers (such as a remote domain controller)--resulting in extremely high call rates in a small-office environment.

Send your comments on this article to Dan Backman at dbackman@nwc.com.