Because of the lower long-distance and infrastructure expenses they offer,
Internet telephony gateways are beginning to become more prevalent in small
multi-branch offices or to communicate with distributors. PUREDATA's RT 201V
Internet Telephony Gateway (ITG) caters to this need with an easily
configurable Web interface or the use of a command line interface. With up
to eight lines per unit, two slots are available, each able to contain four
analog ports as either an FXS or FXO module. The gateway is H.323 compatible
and supports the G.711, G.723, and G.729 compression codecs.
The first procedure that should be done is installing the FXS and/or FXO
modules, which is actually kind of fun. It's almost like playing with Legos
-- just unscrew the lid to one of the two slots and slip the module back so
that it snaps to the aperture.
If you have an Ethernet connection and a Windows 98/2000 PC, you are
actually pretty close to finishing the installation if the network settings
are correct. Setting the IP address for the ITG can be done through a Web
browser. By specifying a particular IP address through your network settings
on your PC and then entering the ITG's default IP address as the URL on your
browser, you are allowed access to the configuration interface after
entering the appropriate username and password. From there, you change the
ITG and gateway to the proper IP addresses. You can also configure most
settings through this point and click method.
From the command line interface, the configurations can also be
accomplished relatively easily. After accessing this interface through
HyperTerminal, making sure that it's set for 19,200 bits per second and
"none" for the flow control, you can just type "Help" to
learn the commands needed for configuring the ITG. From there, the main
settings could be adjusted without much difficulty.
The ITG comes with a four-page quick installation guide so that a user can
set up the initial configurations. This information is accurate and helpful.
Once you access the Web interface, information is given that acts as a
glossary to the different settings that can be performed.
Most of the pertinent information about the RT 201V Internet Telephony
Gateway can be found on PUREDATA's Web site through their eLibrary or via
the CD that comes with the ITG. Simply put, this information is layered out
into informative chapters with many screenshots. It admirably covers
virtually anything that you would want to know about the product.
About the only minor drawback of this documentation is how to access the
proper information about the ITG. The CD lists all of the products that
PUREDATA offers but does it in a way that might confuse users trying to
access specific information, making it a little difficult to navigate to the
file needed. Likewise, while the information on the Web Site is more easily
navigated, the user still needs to know the proper password to gain access
to the information, which may present a slight inconvenience.
The following is a list of the major features of RT 201V Internet Telephony
- Compliant with ITU H.323 specifications, thereby supporting Microsoft
NetMeeting, NetSpeak, WebPhone, and other VoIP software.
- Supports G.711, G.723.1, and G.729ab voice codecs and T.38 fax relay.
- Provides two slots for up to eight analog line connections for
voice/fax over IP applications.
- Supports both FXS interface to phone sets or fax and FXO interface to
PBX or PSTN.
- Fully compatible with TCP/IP Networks -- one 10/100 Base-TX port and
- Setup through Web browser or command line interface with speed
The best way for us to test the RT 201V Internet Telephony Gateway was to
call from TMC Labs (in Connecticut) to a remote location (in this case to
PUREDATA's California headquarters) -- from one ITG to the other. In this
way, we could use the ITG the way it was intended to be used -- as a means
to call other offices in a multi-location business or vendors by creating a
First, we had to set up the dialing plan to place that particular VoIP
call. While some administrators might be more comfortable with using the
command line interface for certain configurations, we felt that the Web
interface would be simpler for these particular tests. We clicked "Dial
Settings" and added the appropriate telephone, hunt group, and
destination settings. This simply involved associating a speed dial with a
hunt group ID and entering the appropriate remote destination IP address.
When we attempted the call, we thought that there might be firewall
issues on our end. The call went through and the PUREDATA representative
could hear us. However, we couldn't hear him. Yep, it was definitely a
firewall issue. We had seen that problem many times before when testing
other VoIP products, so we opened certain TCP and UDP ports. Unfortunately,
we still had the same problem. Our firewall still must have had
Not to be deterred, we took the ITG to our other office so that the
gateway could sit in front of the firewall. We set the ITG up, changed the
appropriate configuration settings (ITG IP address, gateway, etc.) via the
command line interface and were soon ready to try again. This time, the call
went without any issues occurring -- no firewall = success. Now, we were
able to discern the sound quality of our VoIP calls and give it a very
favorable assessment. We could hear the PUREDATA representative perfectly.
Even when we had talked for a while, we only heard a slight echo. Certainly,
users would be pleased with the sound quality.
To test for H.323 interoperability, we called the ITG from a Windows 98
PC, using Microsoft NetMeeting. To do this, we clicked on "Advanced
Calling Options," checked the gateway setting that allowed us to use a
gateway to call telephones, and entered the IP address of the ITG. After
typing a viable extension, the call successfully completed, showing that the
ITG was indeed compatible with H.323 applications.
When we received a second ITG with an FXO module, we set up the gateway
and a dialing plan so that we could call into the FXO module through an
analog Teltone simulator. From there, we dialed an extension located on the
other ITG, and the call was transferred via IP. Then, the call completed at
a phone that was hooked up to one of the FXS ports.
We did this same test again, but this time hooked it up to the Agilent
Telegra Voice Quality Tester (VQT), which is reviewed on page 50 of this
issue. In this way, we could test for delay, PSQM, PAMS, and other scores
that are associated with VoIP. To make a longer story short, the average
delay was ~127ms, average PSQM was ~2.77, and the average PAMS scores were
~4 for listening quality and ~4.3 for listening effort. Keep in mind that
the lower the PSQM score, the better. Below 3 for VoIP calls is considered
good. On the other hand, the higher the PAMS scores, the better with the
highest score being a 5. Over all, the scores for PUREDATA's gateways
indicate quality VoIP calls.
ROOM FOR IMPROVEMENT
The RT 201V Internet Telephony Gateway really doesn't give us too much for
us to harp on, but of course, we do have a few suggestions. For some reason,
we could not find a way to change the default password when either accessing
the Web-based GUI or telneting to the command line interface. Password
changes should certainly be available as well as easily doable. We also
could not edit dial plans. If we wanted to change a plan, we had to delete
and then add a new, corrected dial plan.
We would also like to see some monitoring a pplication incorporated onto
the Web-based GUI or command line interface so that we could see what is
happening as the VoIP call is being connected. This application could also
explain why a call may not have connected so would help a user troubleshoot
a problem. There is a Status screen, but it doesn't actually monitor the
In addition, we feel that there may be some compatibility issues between
the ITG and Windows 2000 that may need to be addressed. On numerous
occasions, we had problems calling from NetMeeting to the FXS card in the
ITG. This anomaly happened only when using a Windows 2000 client, and we
tried it from many different PCs. We had no such problems when trying the
same call from Windows 98 clients.
Lastly, we would like to call from a gateway to the ITG via IP and then
hop off to the PSTN to make a local call. Of course, this feature may
introduce some billing concerns and may increase the ITG's price but would
save a company more money in the long run, making the ITG an even more
Simply stated, PUREDATA's RT 201V Internet Telephony Gateway achieves its
purpose. It allows small and multi-branched offices to make clear, quality
VoIP calls that is easily configurable and is H.323 compatible. In these
days where the economy is less strong, this type of product may be a
blessing, saving businesses considerable expenses. With good quality to
boot, the ITG is certainly a worthwhile investment.
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