October 1997

V/IP Phone/Fax IPGateway
Micom Communications
Corporation
4100 Los Angeles Ave
Simi Valley, CA 93063
Ph: 800-642-6687; Fx: 805-583-1997
Web Site: www.micom.com

Price: $1,795 (for 2-channel analog voice interface card including software).

IP telephony is making a big splash on the CTI scene. As the Internet Protocol (IP) continues to mature and support higher bandwidths, a number of voice and video over IP products have sprouted with the hope of taking away business from the telephone companies. IP telephony gateways are one of the fastest growing segments of the IP telephony market. Such a gateway is a piece of equipment (normally a computer) which bridges the gap between the PSTN lines and the IP network (Internet/Intranet). Voice (and video) is then transmitted over the existing IP network wherever possible — cutting down on long-distance charges.

Micom (a Nortel company), is wellknown for its networking and data integration solutions. They have answered the IP telephony call (so to speak) with V/IP Phone/Fax IP gateway, a new integration product featuring hardware and software designed and developed to provide seamless voice/fax integration over any IP network. V/IP allows companies to capitalize on their currently installed IP networks by carrying voice and fax as well as data on these networks. This solution, available from Micom today, has already proven itself to be feasible.

Before delving too deeply into the review of Micom’s V/IP, we need to define a few telecom interface terms. A Foreign Exchange Station (FXS) provides the signaling for connection to a standard phone, fax, or PBX. A Foreign Exchange Office (FXO) interface emulates a phone and connects to the station side of the PBX or directly to the Central Office. E&M (Ear and Mouth) interface is a popular trunking arrangement used for two-way switch-to-switch or switch-to network connections.

INSTALLATION
We received two 2-channel FXS/E&M analog cards from Micom which we used to create two IP telephony gateways. Our two PCs were Pentium 166MHz machines with 32 Megabytes of RAM running Windows 95 connected to our 10 Mb/s network with static TCP/IP addresses. To simplify matters, we opted to keep both gateways in the same LAN segment rather that having a router in between. We also skipped the RSVP (Resource reSerVation Protocol) and SNMP (Simple Network Management Protocol) features of V/IP to concentrate on the central operation of the product.

A Few Words About RSVP And SNMP
RSVP is used to reserve a certain amount of bandwidth on the network to carry out a transmission. This becomes very crucial when real-time voice transmission is concerned. In order to utilize RSVP for V/IP, the network must be equipped with one or more routers running a ID14-compliant version of RSVP, and the host must be able to perform the signaling required to establish reservations. This is achieved by loading RSVP enabler software such as PC-RSVP (by Intel) in the telephony gateway. PCRSVP requires Winsock 2 for correct operation, but we were told by Micom that Winsock 2 has a few bugs that may hamper RSVP.

SNMP is an effective tool to manage and monitor nodes on the network. V/IP utilizes SNMP to allow central management of all the telephony gateways in the network. In order to utilize SNMP for network-wide V/IP management, the Windows 95 gateways must have the Microsoft SNMP Agent installed. Then a network manager utilizing a network management system product (e.g., HP OpenView) can access and manage all the V/IP gateways in the network.

Network Configuration
Before installing the IP telephony gateways, the Telecom/Network Administrator must consider how the gateways are to be deployed in the network. To that end, the V/IP manual provides a planning worksheet to help the Administrator configure the gateways. Our plan of attack was to connect one gateway to our Nortel Norstar Compact ICS PBX (donated by Nortel through our CTI benefactors program) and connect the other to a regular POTS telephone set. The gateways could have been considered to be far away from each other (for example the PBX in New York and the telephone set in Los Angeles) as long as there was a LAN/WAN connection between them. We completed the worksheet to reflect our plan and prepared to build the gateways.

Gateways
Unfortunately, the voice interface cards are not Plug and Play, but the V/IP manual was very helpful in guiding us to easily configure the cards and install them in the gateways. Here is how the procedure worked for one of the gateways: Before installing the card in the gateway, we first installed the V/IP analog card driver using the Add New Hardware Wizard utility of Windows 95. When the wizard finished installing the driver from the V/IP diskette, it presented us with a window informing us of the settings (I/O, IRQ, etc.) to use for the card and followed it up with a prompt to shut down the PC to install the card. We used the jumper setting instructions in the manual to configure the card with the particular I/O port base address and FXS interface on both channels before installing the card in the PC’s ISA slot and rebooting the PC.

Next we installed the V/IP software on our gateway. We started the PC which was to be interfaced with the telephone set (“phone gateway,” from here on in) and ran the V/IP setup program to install the V/IP software. The setup program located the V/IP card and presented us with a window to configure it (Figure 24). We used our planning worksheet to fill in the requested information. We decided to set up the phone gateway as the Directory Server in our setup.

Directory Server
The Directory Server maintains the central database used to translate between the gateway codes and the IP addresses of the gateways. We also chose to have V/IP auto-started every time the gateway is rebooted. V/IP created a configuration file using our entries and initialized the voice interface card channels. We plugged in a telephone set to channel 1 of the voice interface card, thus completing the phone gateway setup. For the PC which was to be interfaced to our Norstar PBX (PBX gateway), we performed the same installation procedure, the only difference being specifying the phone gateway’s IP address as the Directory Server during the configuration process. We connected a trunk line of the PBX to channel 1 of the gateway. At this point our telephony gateway setup was completed.

DOCUMENTATION
The beta version of V/IP for Windows 95 was shipped to us with a preliminary user’s manual for the analog voice interface cards. The manual’s organization and contents were excellent, and we were very impressed by its attention to detail. The V/IP manual covers the installation, configuration, and administration of the voice interface card as well as the V/IP configuration program. There are a good number of examples and plenty of screenshots to guide an installer through building and configuring the gateway. The help facility of the V/IP configuration program is complete and very well organized. The only drawback of the help facility is its lack of context sensitivity. Given that the product was still in beta during our review, we hope that this issue is addressed by the time V/IP for Windows 95 is released.

FEATURES
Hardware
V/IP voice interface cards interface with the PBX or key telephone system. These cards, which are available in analog and digital interface models, take voice and fax signals from the existing telephone system and convert them into a digital format that can be processed by any standard PC. They feature 16-bit ISA compatibility and utilize ClearVoice digital signal processor (DSP) technology, which digitizes analog voice signals using the G.729 voice compression standard. There are four analog voice interface cards:

• Single Channel FXS/E&M Card.
• Dual Channel FXS/E&M Card.
• Single Channel FXO Card.
• Dual Channel FXO Card.

V/IP digital voice interface cards offer T1 and E1 interfaces with up to 24 and 30 channel connections, respectively. There are four V/IP digital voice interface cards:

• Four-Channel T1 Card.
• Four-Channel E1 Card.
• Four-Channel Expansion Card.
• Two-Channel Expansion Card.

Combining these cards in a PC allows configurations that match the required channel densities at any given site.

Software
The V/IP software performs all callrelated functions in PCs and servers running popular operating systems such as: Novell’s NetWare; MSDOS; Microsoft’s Windows 95; and Microsoft’s Windows NT. Software functions include system configuration, call management, setup and termination, voice support, router/WAN priority protocol, and embedded SNMP network management.

OPERATIONAL TESTING
Upon rebooting the systems, the V/IP process auto-started (on both) pursuant to our request. The V/IP icon in the system tray indicated that the program was up and running. Placing Calls To verify the operation of V/IP, we plugged in two telephone sets into the two channels of the voice interface card in the phone gateway. We pickedup the phone connected to channel 1 and made a call into channel 2. The V/IP voice inter-face card can generate an array of tones associated with telephone equipment (such as dial tone, busy tone, ringing signal, and DTMF) so making a call was as natural as using a regular POTS line. Dialing channel 2 was accomplished by dialing the gateway code followed by the channel number which made the phone on channel 2 ring. We answered the call and started a conversation between the two phones. There was a little noticeable lag between the transmitting and the receiving of voice (which we attributed to the compression algorithms carried out by the onboard DSPs) but we found the voice quality excellent.

Next, we tested the system between the phone and the PBX gateways. We placed a call from the phone gateway to the channel on the PBX gateway where the PBX was connected. Again, this was accomplished by dialing the gateway code followed by the channel number. V/IP was able to correctly translate the dialed number into the IP address of the PBX gateway and make a call into the PBX. We picked up the call from one of the PBX phones and noticed that the voice quality was just as good as our first test — impressive, considering we have a high-traffic network. We now turned our attention to the V/IP Configuration Program.

Configuration
The V/IP Configuration Program can be accessed by double-clicking the V/IP icon on the system tray. This presented us with the main window displaying the available voice interface cards and the channels in the system (Figure 25). From this screen, one can manage and monitor the voice interface cards as well as add and remove cards to and from the gateway. We liked the Explorer-like layout of the screen and found the program very easy to work with. Three levels of configuration are available from here: gateway, voice interface card, and channel configuration levels. TheV/IPSystem Configuration screen (Figure 26) can be accessed either through the button bar or the Configuration menu. From this screen, we could review and modify some of the essential settings of the gateway, such as the gateway code, the directory server, and number of digits configurations. Also, from the Configuration menu one could select the SNMP/RSVP option to configure those aspects of the gateway. Finally, new cards can be added to the gateway or cards can be taken away from the Configuration menu. Essentially, this option invokes Windows 95 system programs to add or remove hardware.

We were also able to get statistical information about the gateway by using the Status/Statistics menu item. From here we obtained the system’s statistics (Figure 27) as well as itemized statistical data on the channels. Another item on the Status/Statistics menu list was the Phone Directory option. Choosing this item brought up a screen displaying the translation table between the gateway codes and the gateway IP addresses in the network (Figure 28).

Configuring a channel was as easy as a right-click on the particular channel and selecting the Configuration menu item. Upon choosing this menu item, the displayed channel configuration window (Figure 29) allows the administrator to change many settings of the channel including channel number, voice/fax capability, line impedance, and fax baud rate.

The V/IP configuration program comes with an array of diagnostics tests to troubleshoot possible problems. For starters, there are options to reset the voice interface cards and the channels individually. Each channel can also be taken through a set of diagnostic tests, including local selftest, local loopback test, and remote loopback test. To start any of these tests, one can right-click on a particular channel and select the desired test from the Diagnostics menu. Doing so changes the status of the channel to test mode. Verifying the channel’s correct operation then involves speaking into a telephone set connected to the channel and being able to hear the echo clearly. At the end of our diagnostic tests, we selected the Terminate Test option to return the channel to its normal status. From the Diagnostics menu, one can select the Level Adjustment option to adjust input/output levels of the voice interface card. This action may be necessary to correct echoing or other voice impairments.

Creating A Hunt Group
One of the more interesting V/IP features is the ability to pool all the available channels to form a hunt group. This can be a real benefit as it is no longer necessary for the callers to concern themselves with which channel they dial into. We set up our PBX gateway channels as a hunt group by setting b o t h c h a n n e l numbers to 0.

Then, from the V /I P S y s t e m Configuration screen, we set the Channel Digits to 0. Dialing into the PBX gateway was now a simple matter of dialing the gateway’s code from our phone gateway without having to specify a channel number. When all channels of a V/IP gateway are members of one hunt group, the incoming calls to this gateway are routed in a round-robin fashion starting with card number 01, channel number 01.

Fax Capability
Finally, we tested the fax capability of V/IP using fax machines installed at each gateway. V/IP handled the fax transmissions as well as having them done over regular POTS lines.

Other
We would like to mention that by using FXO cards, a gateway can be set up to allow remote outdialing. The FXO card is interfaced to the Central Office lines, CENTREX, or PBX station lines. In this configuration, an employee from a remote office can get a dial tone on a remote PBX and can also be called on an assigned extension on that PBX. Of course, the same V/IP Configuration Program is used to monitor and administer the FXO card.

CONCLUSION
Micom’s V/IP is proof that IP telephony gateways will encroach more and more into the telecom landscape. With high-quality voice and fax transmission, easily installed and administered hardware and software components, and multiple interface options, V/IP is an excellent choice to enhance corporate telecommunication capabilities while reducing cost. It should be noted that V/IP (along with other telephony gateways on the market today) offers peak performance when deployed in a managed network (Intranet) since companies can configure their networks to best support the gateways. Companies who already have data networks between their offices should realize the benefits of V/IP rather quickly. Micom has confirmed that the Windows NT version of V/IP is currently under development and will be released in the very near future.