“Testing” in the CTI industry often means using software from Hammer
Technologies. Hammer’s famous IT and LoadBlaster (formerly called the ISG series)
products have gone through many upgrades, representing support for new protocols,
additional testing scripts, and voice over IP (VoIP). The newest software version, 2.3.1,
includes better fax and SS7 support, Year 2000 compliance, remote audio monitoring,
improvements in the GUI and in security, and a simplified installation process. This
version also includes many new bug fixes and upgrades for the Hammer VB program.
For readers who aren’t familiar with Hammer, their software is best categorized as
a toolkit. The high-end version is the Hammer IT, which comes with the Hammer VB module,
and options for SS7, VoIP, fax, etc. The low-end version is the LoadBlaster, which
includes the graphical TestBuilder program, but doesn’t have as many advanced
features as Hammer IT. Hammer IT is designed for highly technical professionals, while the
LoadBlaster is designed for less technical staff.
Installation
For a real-world installation, we decided to upgrade a Hammer IT system in our
lab (popular older versions included 1.5, 2.1.x, and 2.3, or 2.2.1 for ISG systems). The
system software on our machine was about six months old, and its VoIP software was left
over from an earlier beta installation.
The first step in the upgrade is uninstalling the VoIP and SuiteMaster applications, if
you have them. Next, run the DBClean Suite on 2.3 installations or the DBClean Utility on
installations of 2.1.x and older.
The manual suggests applying the Windows NT Service Pack 4 as the next step, although
Microsoft has since made newer service packs available. Once this is done, users need to
stop several Hammer services and processes, and uninstall InfoMaker and its related
applications. Finally, reinstall the InfoMaker software and the Hammer software and,
optionally, reinstall SuiteMaster and the VoIP suite, version 1.0.1. Reapply the NT
service pack, as well.
Be aware that there are database management issues, which are discussed extensively in
the documentation. The entire upgrade takes less than an hour. Reboot when you’re
finished. Also, before the first use of the new software, remember to run the Hammer board
utility, not just the standard telephony loader.
Hammer systems are sold turnkey on industrial PCs, so users need not worry about supplying
a properly equipped system of their own. Hammer Systems’ run on Windows NT
Workstation 4.0 and are equipped with a minimum 300 MHz Pentium II, a passive backplane
computer with 10 PCI and 9 ISA slots, 128 MB of RAM, 4 GB of hard disk space, a 56K
internal modem, a 10/100 PCI or ISA network card, floppy and CD-ROM drives, a 17”
monitors, and rack mounting hardware.
Documentation
The installation and configuration guide stands out among Hammer’s
seven-part documentation set, which includes chapters for chassis assembly, release notes,
upgrading, installing from scratch, technical notes, system configuration, and the Hammer
database. We especially liked the release notes, which in places read more like a
“read me first” guide.
This guide contains information on new features, resolved issues, special
considerations, and known problems. The documentation for the VoIP system is extremely
good, featuring its own release notes section, plus a user’s guide, which is one of
the best we’ve ever seen. After completing the installation, we immediately checked
out the online help and were pleased to see several different how-to books for scripting
among the various protocols. A help button on the main interface toolbar provides
context-sensitive help for most of the system’s features and menus.
There is no user’s guide for the system as a whole, however, neither printed nor
online. Many of the pieces are in the documentation set, and they are very good, but much
information is missing, and none of it is organized into a central repository. At first we
assumed that there had been an oversight of some sort. After all, the VoIP suite and
Hammer VB language manuals are excellent — who wouldn’t include a centralized
user’s manual with such a complicated product? A Hammer representative confirmed that
no such manual exists, although one did exist in previous versions and is planned for
future versions.
Regardless of how advanced a product’s audience may be, a vendor should never
assume that a user’s manual is unnecessary just because users can figure it out
themselves or because parts of the relevant information are contained elsewhere. It’s
probably true that an experienced CTI technician can figure out the Hammer product based
on a combination of the online help, the subset user’s guides, and a mix of their own
deductions, patience, and experimentation. A less technical person might have some
difficulty, though. The online help in some areas is exceptional, and it’s clear that
a lot of effort was put into it. Still, the various components of “help” are
disjointed here. A single, well-organized user’s manual should not be an option; it
should always be included.
Features
As we mentioned earlier, Hammer software is a sort of testing tool. The IT
version is more of an overall CTI feature tester, and the LoadBlaster version is more of a
stress tester. Still, the 2.3.1 software applies to both systems. Because we’ve used
the former and current versions of this software in our lab for many different kinds of
product reviews, we decided to replace our traditional “Operational Testing”
portion of this product review with a brief report on our own real-world usage of the
system.
Starting the Hammer system for normal usage is two-step process. First, once your
operating system is booted and all events, services, and start-up programs have cleared,
users need to run the telephony loader application. This application initializes all
boards and otherwise prepares the software and hardware. Next, choosing the Hammer icon
opens the main program, which asks you to pick the correct server to log on to, and then
defaults to the Library Manager view. (The desktop on our IT system also has an icon for
the VoIP suite, which has its own interface.)
The Interface
The main interface is well organized. Every window is resizable, and features are
easily accessed with the seven pull-down menus and a toolbar. The Library Manager is on
the left side. Highlights include a recently used list under the File menu, an expand
all/collapse all feature for the various suites and scripts, a custom view creator and
graph editor, and a list of easy-to-remember shortcut keys for switching to other views.
These screens provide access to many options:
- The Library Manager is a tree structure, divided into common and private categories. The
common folder includes suites, scripts, vocabularies, and voice files, many of which can
be right-clicked for additional options, such as open, create custom view, display/edit
custom view, monitor custom view, graph and properties. The default view shows which
suites are running and their respective status. It also shows logged messages on a
per-channel basis, and it allows you to start, stop, suspend, and resume any or multiple
channels.
- The Scheduler schedules and lists all pending tests and allows you to use a
drag-and-drop convention to schedule suites for testing.
- The Disk Space Monitor and Channel Monitor screens are simple; the Disk Space Monitor
shows a graphical view of hard disk space, and the Channel Monitor selects which channel
to listen to over your PC speakers.
Other Features
For example, a new GUI for the SS7 protocol configuration replaces the older,
manually edited text files. New SS7 diagnostic scripts have also been added. There are
options for software-locking the Library Manager, for Windows 95 client support, for
database duplication spanning multiple servers, for “asterisk” and
“pound” key support, and for improved error code descriptions.
Also, there is improved ISDN 5ESS support, improved Group 3 fax support, increased port
capacity for speech recognition, and several new Hammer VB extensions. SuiteMaster, an
optional component, is a graphical VB test-building tool and is backward compatible to
Hammer systems running software version 2.1.3. SuiteMaster looks and works much like the
popular CTI app-gens from companies like Pronexus, Artisoft, and Parity.
Operational Testing
SuiteMaster is to the Hammer IT what TestBuilder is to the Hammer LoadBlaster.
It’s important to note that the VoIP software version 1.0.1 also has new fixes and
improvements. Internally, we use this suite to conduct our gateway testing for INTERNET
TELEPHONY� magazine.
Latency Measurement: Our testing configuration is simple, but it’s also
effective and reliable. First, we measure latency, initially at the lowest common protocol
(analog), and then at other protocols like T1 or ISDN, depending on the nature of the
individual gateway. Latency measurements work by listening for DTMF tones that have been
played and time-stamped at the originating Hammer channel. These tones travel to the local
gateway, where they are compressed, packetized, and sent across the network. At the remote
gateway, the packets are reassembled, decompressed, and sent to the terminating Hammer
channel, where they are time-stamped again.
The difference between time stamps equals the latency. The network path consists of a
connection stemming from one channel on the Hammer system to the first gateway, a
compression phase at the gateway itself, a network connection to the second gateway, where
the speech undergoes a decompression phase, and a final connection from the second gateway
to a terminating channel on the Hammer system. This provides us with five distinct phases
that all speech would travel across: two connections, a compression and decompression
phase, and a network path connecting the gateways.
Our goal is to examine only the latency introduced by the gateways because of
compression and decompression algorithms, so we need to minimize the latency effect of the
analog and network connections. Better gateways don’t just compress and decompress
the voice, they do it as quickly as possible to minimize any latency introduced by using
techniques like double-packeting and increasing packet routing priorities
The IP network between two gateways is easy to manage because we use a
“clean” network with only a 10-BaseT hub connected only to a PC running
gatekeeper and network management/degradation software. Meanwhile, the circuit between
each gateway and the Hammer channels often includes a CO line simulator as well, depending
on whether the gateways involved are FXO or FXS types (if analog). Otherwise, we use an
ISDN or T1 simulator in the circuit. We also subtract from the final measurements any
latency that the simulators introduce.
PSQM Scores: Another important component of our testing is the PSQM scores,
which determine the quality of speech according to the benchmark assessment of a group of
human judges endorsed by the International Telecommunications Union (the ITU-T P.800 and
P.861 standards). An algorithm plays sound clips chosen for the range of sounds that they
produce, not for the clips’ actual meaning, which tend to have an eerie and
nonsensical nature. Each of the sentences is read in a male, female, and child’s
voice, encompassing a range of tones. Like the DTMF tones in the latency test, the sound
clips are compressed, packetized, sent across the network, and decompressed by the remote
gateway, which plays the clips back to the Hammer system. The Hammer system then takes
this signal and passes it to the PSQM algorithm along with the original prompt from the
voice library. The PSQM algorithm compares the received prompt to the original one and
reports a PSQM score.
VoIP testing is only a small and optional portion of the Hammer software, but it’s
representative of real-world situations, along with load testing, which in many cases is a
more common scenario. Basically, by continuing to increase the number of calls sent over a
network path over which your company’s product is simultaneously running, you can
pinpoint processes, functions, and other incidences when your product will fail or not
perform to your standards. The Hammer engineers continue to introduce new features, like
SS7, H.323, and fax support, which make their own product much more useful.
Room for Improvement
Many features that some CTI testing packages lack (like remote access,
customization options, and high/low-end versions) are standard in the Hammer 2.3.1
software. We feel that the one area where this software can be improved is the look and
feel of the GUI. We like that the multiple interfaces are consistent throughout the
product, but we feel that in many places they are inconsistent with standard Windows
conventions — we’re especially looking forward to seeing if and how this may
change next year when many NT 4.0 applications begin to support Windows 2000.
Hammer’s interface uses windows within windows, which isn’t necessarily a bad
thing, but becomes a problem. When you open or resize one sub-window, the other windows do
not change with it, which creates a messy desktop.
We feel that the 2.3.1 software wastes a lot of desktop space and generally seems coded
with little input from a graphic artist. Color is now introduced with a gray background,
and though it is an improvement from previous versions, it’s still unpleasant to
stare at for any length of time, especially when you’re in the Hammer VB mode. A more
compressed and modernized GUI would be helpful.
For actual performance issues, however, we are satisfied that the Hammer engineers have
either optimized everything or are already aware of and addressing known problems. We also
feel that, when it comes to the interface, most serious developers feel that they’ll
tolerate (but still deserve better than) the status quo. Finally, there are multiple
documentation problems, as discussed earlier.
Conclusion
At TMC Labs, our Hammer systems are our most valuable equipment. We could not do
our jobs without them. In fact, Hammer may be the only company in the CTI industry that is
not exaggerating when they claim to be “an industry standard,” and we personally
will endorse that claim. True, in some aspects, Hammer competes with companies like Zarak
Systems, Ameritec, and even some mainstream companies like Hewlett Packard, but Hammer is
certainly the leader for developer-oriented CTI testing. Despite its documentation flaws
and questionable interface design, it is an invaluable lab tool that we highly recommend
and to which we proudly grant our Editor’s Choice award. |
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