When the huge bluish-green anvil was delivered to TMC Labs,
we put it in the only place it could fit � in front of what we
affectionately call �The Green Monster� in reference to the famous wall
in Fenway Park, Boston. Our wall effectively blocked off TMC Labs from the
rest of the editorial department, allowing us to snake cables and wires
across the lab without fear of others tripping over them. But now, actually
rising above our Green Monster was a rack mountable system that incorporated
an entire Cisco AVVID IP Telephony solution within it. This included the
three main servers associated with the solution: CallManager, Unity, and
Personal Assistant. These three servers could be viewed through a flat
screen monitor, switching to each individual server through a console.
To complete the network, the servers were all hooked up though a Cisco 3600
gateway and a Catalyst Ethernet switch. End points, such as the Cisco 7940
and 7960 IP phones and the Cisco IP SoftPhone, were connected to the demo
network and could call one another once each was configured. As a whole, the
system emulated a live network of a company that has a headquarters and at
least one branch office.
THREE SERVERS, SIMILAR INTERFACES, ONE INTEGRATED SYSTEM
Simply put, CallManager is the heart of the AVVID IP Telephony solution. It
manages the entire network, whether dealing with gateway, gatekeeper, or IP
phone configurations. The amount of configurations available can be daunting
to an administrator as there is much to learn about it. A case in point is
that we recently received a well laid out 700-page behemoth of a book that
only covers the fundamentals of CallManager for the Cisco IP Telephony
solution. Accompanying that book is another mammoth book focused on
configuring and training administrators about the telephony solution. But
when examining the Web-based GUI, we found that CallManager really wasn�t
so difficult to figure out, especially once the initial configurations were
set up. Yes, we had many options to choose from, but these were in the form
of fairly understandable terminology organized within the eight pull-down
menus. With our trusty, albeit large, reference books and the CallManager
help files, we were able to configure and add users to our little network.
We were also able to set up three VLANs: For the Call Manager cluster, for
voice, and for data. The main idea here was to separate voice and data so
that voice to data streams could be blocked. In this way, voice packets and
data packets could not interfere with each other.
We even employed transcoding resources when emulating calls between
headquarters and a branch office that were using different audio compression
codecs � hence, they could communicate even when the headquarters was
using G.711 while the branch office was using G.723. We also emulated calls
going over a WAN to use G.729, but within each office, we set G.711 as the
codec of choice on each IP phone. Since there could be large amounts of
traffic over a WAN, using a heavily compressed codec, such as G.729, would
make sense but may be unnecessary within an office setting. In this
scenario, a call from headquarters was converted from G.711 to G.729 and
then reverted back to G.711 when the voice packets reached the branch
office. Our test calls went through without a hitch.
For unified messaging, Unity delivers on voice mail essentials while also
adding voice mail and faxes to traditional e-mail applications, such as
Microsoft Outlook, or accessing them through the Internet or a phone with
the use of text-to-speech capabilities. Personalizing voice mailboxes,
configuring personal greetings, and navigating to other Unity features is
done with a similar look and feel to that of CallManager. TMC Labs did an
extensive review on Unity before it was bought by Cisco from Active Voice in
the February 2000 issue of Communications Solutions Magazine�. We
recommend reading the review since it is still applicable for obtaining more
information about the main functionality of the system. The review is
available at www.tmclabs.com. The
feature chart for the Cisco IP Telephony solution lists some Unity features
as well.
Personal Assistant is an add-on application that can redirect incoming
calls based on the rules that individual users create. Depending on the user�s
rules, calls can be handled differently and sent to different phone numbers.
Users can even specify specific callers to call a wireless phone for
instance whereas another unspecified number would go to voicemail. In
effect, Personal Assistant is an advanced version of one-number follow-me
functionality. It even incorporates speech recognition for speech-enabled
directory dialing and performing common voicemail operations through a
speech interface to Unity. Maybe most impressive is the voice-activated
conference calling for up to six participants.
We took a look at Personal Assistant from both an administrator and user�s
point of view. Just like CallManager and Unity, Personal Assistant used a
Web interface that was familiar, especially after using the other
interfaces. We set up destinations, an address book of users, and caller
groups. Then, we added rule sets based on caller identity, time of day,
calendar status, and destination of the call. This proved to be an easy task
and a very effective method of organizing calls and reaching recipients of
the calls when they are away from their desks.
IP PHONES
As far as IP phones are concerned, the Cisco 7940 and 7960 are quite easy to
use with functionality that compares to other top of the line IP phones.
Merely by pressing the appropriately set button, the user can perform just
about any telephony function, including redialing, transferring, holding,
and even conferencing calls. Obtaining voice mail, changing phone settings,
accessing directories of callers, and using speakerphone are also done with
a press of an easily identifiable button. Perhaps the most impressive though
is the services button, which can incorporate XML functionality into the
phone settings.
We tested many of the telephony features, calling from one phone to
another via the Cisco Skinny protocol. Skinny is literally a skinned down
version of H.323, so while a Cisco IP phone may be interoperable with other
H.323 IP phones, this may not always be the case. However, the Cisco IP
phones do also support SIP, and we have tested these phones with success
with most other SIP phones. Unfortunately, we could not do so through the
Call Manager, which does not yet support SIP.
We connected a PC to our small network so that we could use the Cisco IP
Softphone with the Call Manager to receive and call the other IP phones. The
graphical interface looks somewhat like the hardware Cisco IP phones. As a
matter of act, they have the same feel to them except for the obvious
hardware/software difference � the softphone used desktop call control
with collaboration tools and a headset while the hard IP phones used the
services button for XML applications and a handset. The softphone had very
similar functionality as its hardware counterparts and seemed almost like a
cousin to the Cisco 7940 IP phone.
Both the softphone and hardphone models took some time to power up. From
there though, the hardphones were reliable, but the softphone version we
were using still seemed a bit flaky, at least on our Windows 98 PC.
Sometimes, we could not end a call and the software froze up. In addition,
there were occasional audio conflicts with other applications, but we could
not figure out which other applications these were. Exiting the software
through the Windows Task Manager and then going back into the program solved
the former issue, whereas the latter issue was solved with a reboot of the
Windows 98 PC. We should also note that the Cisco IP Softphone only works
with Windows 98 Second Edition as well as ME, 2000, and XP.
As far as sound quality is concerned, there often was a noticeable echo
and static when making a call with the softphone. Fine-tuning and optimizing
the audio settings greatly improved the sound quality, and a better sound
card and headphones improved the quality even more. Even so, the hardphones
usually showed slightly better audio performance. With that said, the Cisco
IP softphone still has the flexibility of other softphone applications with
more functionality than most.
CONCLUSION
For the large corporations that are its core market, the Cisco AVVID IP
Telephony solution has an excellent blend of voice and data convergence. It
is an easily scalable solution with an abundance of features and quality
add-on applications. However, the solution is not targeted at smaller
companies with less than a 500-port usage, which narrows Cisco�s market
potential, especially since 80 percent of companies are small-to-medium size
businesses. Cisco does have applications that can be used with smaller
networks, but thus far, they have not focused their attention on these
products. It may be time to do so, since the Cisco AVVID IP Telephony
solution offers much of what many smaller companies need and the scalability
potential would almost be limitless for growing companies.
[ Return
To The May 2002 Table Of Contents ]
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