Most of us know that a slow Internet connection can make a simple, pleasant task seem
like an exercise in futility. But let’s look at a specific example: Imagine that you
have a 28.8 Kbps connection, and that you’ve started downloading Internet Explorer
(15 megs). You could leave for a cup of coffee, and return to find that the download is
still incomplete. Worse, you could return three hours later, from a stroll in the park,
perhaps, and then find that the connection has timed out, and that you need to start the
download all over again. So much for productivity.
When it comes to sluggish Internet connections, some companies try to make the best of
things by resorting to a cost-effective workaround — running a proxy server with a
single analog dial-up connection. The advantage of a proxy server is that it can provide
excellent caching capabilities, which can boost apparent bandwidth. Some companies get by
with a proxy server, at least for a while, even if it serves as many as 50 users, since
only a fifth or so of these users are likely to access the Internet simultaneously. Power
users, however, resent sharing a single proxy connection through a 28.8 Kbps pipe. For
them, the proxy workaround is excruciatingly slow.
Ideally, everyone (not just the impatient power users) would have a faster connection.
A 112 Kbps connection, for example, would certainly be an improvement over a measly 28.8
Kbps connection. The issue, however, is cost. For example, you could go out and buy an
ISDN line with two 64 Kbps connections. Taken together, these two connections would amount
to a single 128 Kbps connection. However, depending on your location, your ISDN provider
might impose per-minute charges, as well as exorbitant monthly fees.
A less expensive alternative to ISDN is to use the analog lines in our homes and
offices. But how can we use these lines to attain super-fast Internet connectivity? One
solution is to deploy a product such as 3Com’s OfficeConnect Dual Analog Router.
Since this product provides built-in dual analog X2 modems, and since each of these modems
has 56 Kbps of throughput, you can multi-link the two X2 modems for a total
"theoretical" aggregate bandwidth of 112 Kbps. And if you use compression, you
can achieve an amazing 400 Kbps!
The OfficeConnect Dual Analog Router is part of a family of OfficeConnect products,
which includes an ISDN version. It is a low-cost, completely integrated solution designed
for small businesses, telecommuters, and branch offices. It gives you complete
configuration flexibility, as well as a built-in four-port hub, which lets multiple users
or devices share the two analog lines. It also gives you a built-in router to handle IP
and IPX, and transparently bridge other protocols.
This product is versatile and flexible. For example, it lets you connect to two
different locations (phone numbers) simultaneously, which means you can download files
from the corporate network while you’re surfing the Internet on a separate
connection. OfficeConnect Remote Dual Analog also responds to bandwidth usage by utilizing
dial-on-demand, so each 56 Kbps line is added or dropped automatically in response to
actual usage. OfficeConnect Remote Dual Analog also keeps your line charges down by using
a full suite of network spoofing facilities to minimize unnecessary traffic over single or
combined circuits.
The product also features Port Address Translation (PAT). With this software technique,
unregistered addresses, which are used on the LAN side, are automatically translated into
a single registered IP address, for use over the WAN. Alternatively, you can use Network
Address Translation (NAT), which enables a whole office to share a pool of IP addresses.
In addition, you also get built-in DHCP (Dynamic Host Configuration Protocol) server
support to assign IP addresses dynamically (so you don’t need to dedicate a separate
PC as your DHCP server). OfficeConnect Remote Dual Analog also features DHCP Relay, which
lets remote dial-in users, such as telecommuters, use IP addresses from the corporate DHCP
server.
INSTALLATION
OfficeConnect should take no longer than 30 minutes to set up and configure. It is, after
all, something an end user could find within a retail computer outlet. In fact, a couple
of our engineers saw stacks of 3Com OfficeConnect units at CompUSA.
Unfortunately, we ran into a few difficulties, and our installation took a bit
longer than 30 minutes. We should point out that the difficulties we encountered had
nothing to do with the GUI of the administration program. The GUI was excellent. Rather,
we were held up by the product’s less-than-clear documentation.
DOCUMENTATION
The documentation attempts to help the customer plan the
installation. A good idea. Pre-install planning can result in speedier setups and increase
the chances of a successful installation. Sometimes, everything actually works on the
first try.
We weren’t so lucky, however. We had some trouble
following the setup instructions, particularly during the telecommuting setup. (See
Operational Testing for details.) What threw us wasn’t that the documentation assumed
some basic networking experience. Rather, the problem was that we had to figure out some
unfamiliar terms, which the documentation never fully explained.
In addition to the written documentation, 3Com provides an
Acrobat file for the CLI (command line interface). The file, which is 159 pages long, is
quite complete. All the same, we would like to see 3Com add a quick reference guide,
something that would list the CLI’s most common commands.
FEATURES
Provides high-speed connections to the Internet and corporate networks. (The product
achieves near-ISDN speeds — without ISDN lines.)
Supports multiple users and devices with an integrated four-port hub. (You can connect a
small network right into your OfficeConnect Remote Dual Analog without having to buy and
install an external hub.)
Supports multiple protocols with a built-in router. (At no additional expense, you get a
powerful router to segment and route your IP and IPX protocols, plus the ability to bridge
other protocols.)
Provides integrated DHCP, PAT, and NAT support, which makes it easier and less expensive
to set up and share a pool of IP addresses.
Reduces online charges. (For example, the product’s dial-on-demand feature can
reduce monthly telephone bills and ISP connection charges.)
Provides four 10Base-T ports.
Provides four LED indicators for troubleshooting and status information.
Supports Hi/fn LZS, Microsoft, and Ascend compression algorithms. (PPP compression
algorithms are automatically negotiated with other devices.)
Authenticates PPP, callback connections via PAP and CHAP.
Regulates access through packet filtering.
Provides LAN-to-LAN spoofing.
Provides telnet with password support.
Facilitates authentication and accounting. (The product includes flash memory with
directory of users, passwords, services, and configuration information, and external
Radius authentication server.)
OPERATIONAL TESTING
We wanted to integrate the OfficeConnect to our existing LAN, so
we drew a RJ-45 network cable from the first port of the OfficeConnect to another hub in
the lab. Since we were going from hub to hub, we used a crossover network wire which
swapped wires 1 and 3, and wires 2 and 6. We got a green light on the OfficeConnect, so we
were all set to go.
Assigning An IP Address
We have a DHCP server in our network, so we had to make sure the
DHCP functionality of the OfficeConnect was disabled. (We needed to prevent OfficeConnect
from assigning IP addresses to our computers.) Instead, we assigned the OfficeConnect unit
a static IP address of 192.0.0.34. (We exclude addresses 192.0.0.1 through 192.0.0.100 for
printers, servers, and other network devices that do not support the DHCP method of
attaining an IP address.)
GUI-Based And CLI-Based Setup Options
We loaded Netscape Navigator and entered "192.0.0.34"
in the URL box, which immediately brought up the 3Com HTML-based administration GUI. From
this HTML-based GUI we were able to modify and configure various settings. We used
3Com’s wizard to easily and quickly set up both dial-in and dial-out user accounts.
The OfficeConnect unit also lets you use a CLI (command
line interface), either by a serial link from a PC to a serial port on the OfficeConnect,
or by telnet, over any TCP/IP network. If you use the telnet option, you work with a
simple text-based GUI (terminal screen) instead of a graphically rich HTML GUI display,
which would appear within your favorite browser. Thus, using telnet is a bit more
challenging. On the other hand, this method has its advantages. For example, it could
actually let you set up various OfficeConnect parameters more quickly. We give high marks
to 3Com for giving users a choice between simple text-based commands or HTML for
administrating the OfficeConnect.
Configuration Settings
With OfficeConnect, you can take advantage of several
configuration options. You can set it up for a single telecommuter with an Internet
connection on the second line, for two telecommuters, or even for an Internet router
utilizing both X2 modems for "shared" high-speed Internet access for your
office.
We set up one account — entering the user name,
password, and phone number — so that we could connect to one of our local ISPs. By
the time we were done configuring everything, we had taken up only ten minutes (with
virtually no manual reading). Then, we got started testing the OfficeConnect. However, we
soon encountered some difficulties with the configuration settings we had chosen.
Simultaneous Dial-In/Dial-Out
For our first test, we tried the method where you can use one
port on Office Connect to dial-in, and OfficeConnect uses the other port to automatically
dial-out to the local ISP. With this method, you can access your corporate network and
simultaneously surf the Web, using just one modem in your PC.
We set up the username and password that the remote
user would need to dial-in to the OfficeConnect, and we set up the username and password
that the OfficeConnect would need to dial-out to the ISP. We also set up a new dial-up
networking connection from a Windows 95 machine and dialed into OfficeConnect, which
picked up the line. Then, for some reason, OfficeConnect would hang up before the modems
could even begin "handshaking" or negotiating.
We noticed that even though it disconnected the Windows 95
machine, OfficeConnect would, for a moment, hang on to the line, since we could hear a
dial-tone through OfficeConnect’s internal modem speakers. Eventually, however, we
would hear the infamous "Please hang up now ... This is a recording." At this
point, OfficeConnect would finally, truly hang up the line.
Apparently, the OfficeConnect would send a disconnect signal
of some sort to the remote end, or briefly perform some sort of flash hook which would
disconnect the remote dial-up modem. Yet it seemed the OfficeConnect would think it was
still connected to the remote modem dialing in, since we could hear the OfficeConnect
modem attempting to negotiate. (In this case, it was trying to negotiate with dial-tone).
We were puzzled as to why it would do such a thing, so we checked a few parameters from
the HTML administrator.
One thing we noticed was that OfficeConnect, by default, would
set the auto-answer to "no answer." Odd, we thought. Why, if auto-answer was set
to no answer, would the modems still answer? Perplexed, we decided to set the number of
rings to "1" before answering, just to see what would happen. (For those
unfamiliar with AT commands, using HTML commands to set the number of rings before
answering is a bit easier than using the cryptic registers, such as "S0 = 1" to
set auto-answer to 1 ring.) We tried setting the second port to answer after the first
ring, but received an error message. This is a minor bug, which we suppose 3Com is fixing.
In any event, we again tried to connect, and this time we
noticed that the modems negotiated for a bit longer, but again, ultimately, we were
disconnected. At this point, we suspected a protocol problem. Either that, or our user
configuration lacked the proper TCP/IP settings. We didn’t have much success finding
the information we needed in the manuals, so we called 3Com technical support. The
technical support person figured the best way to troubleshoot was to set up a brand-new
user with settings that he was positive would work. So he had us set up a new user called
"3Com" with various settings, and then he tried dialing into our OfficeConnect
from his office. The 3Com OfficeConnect router summarily disconnected on 3Com. Talk about
irony!
The technician found all of this quite a puzzle. So, he
escalated the call to another technician, an OfficeConnect specialist. We were told this
technician would give us a call back. In the meantime, we were offered, for our
edification, a log file called "ppp.log," which contained a log of the ppp
events occurring during the dial-up process.
A few hours later, we received a call from 3Com, and the
OfficeConnect specialist had us troubleshoot the settings. Apparently, we had an incorrect
setting for some of the IP addresses. The problem was that TCP/IP and PPP were failing
with an invalid local IP address configured for the dial-in user. The local IP WAN address
was incorrectly set to 255.255.255.255/h (dynamic). It should have been set to unnumbered,
0.0.0.0/h.
In addition, the default setting for the remote WAN IP address
was incorrectly set to "negotiated," as opposed to the correct setting of
"specified," with values 0.0.0.0. The documentation was not at all clear on this
issue. The Telecommuting Access Planning form (3Com’s Preferred Method) in the manual
had indicated that we should set the local WAN address to dynamic, which resulted in the
incorrect "255.255.255.255/h (host based/dynamic)" setting. In addition, the
documentation stated that the remote WAN IP address should be set to "learned,"
whereas in our case, we needed a setting of "specified," with values 0.0.0.0.
Eventually, we learned that we should have used 3Com’s
Alternate Method, which was listed on the next page. However, this was far from obvious.
The documentation for the various parameters, including IP methods, was unclear. Several
information boxes were blank, and hence provided no guidance, which is why we tried the
Preferred Method. And the first 3Com technician was as confused as we were, since he made
the same mistake we did in setting the local IP WAN address to dynamic, as well as the
remote WAN IP address to negotiated.
But no matter. The 3Com technical support was very helpful,
not to mention friendly and patient. (They worked with us for more than two hours before
we finally resolved our problem.) Once we changed the two incorrect configuration
settings, we were able to connect to the OfficeConnect without any problems. Still, it
should be possible for users to accomplish such a simple fix on their own. Better
documentation would help.
Anyway, we went on with our test. We connected to line 1, and
OfficeConnect automatically dialed-out on line 2 to our local ISP and established a
connection. We were then able to access the corporate network, as well as transparently
access the Internet, since the OfficeConnect Router "routes" Internet address
requests coming from the PC on line 1 to the Internet dial-up connection on line 2. This
is a great feature for telecommuters, since it saves them the trouble of disconnecting
their modem from the corporate network and dialing their ISP to access the Internet.
Multi-Linking
Next, we wanted to try the really cool stuff, which was utilizing OfficeConnect’s
multi-linking capabilities. We didn’t have a local ISP that supported the X2
standard, so we settled for an alternative test. We had a telecommuter dial-in to
OfficeConnect using two phone lines, and then we multi-linked the two lines.
Before going further, we should note that we did not get a 56K connection on
either line. In fact, we did not get even 45 Kbps on either line. The problem is not the
56K standard (which the ITU has recently resolved), but rather the nature of the phone
network. The competing 56K standards, which are now formalized into one universal
standard, still require that one, and only one, analog-to-digital conversion occur. When
you dial-in to your ISP, you are going analog-to-digital to the CO, and then
digital-to-digital from the CO to the ISP’s modem rack. In this case, you are fine,
and will in all likelihood achieve 40-53 Kbps throughput.
The problem is that with our tests, we were dialing from our 56K modem to the CO, which
was then routed to our plain old vanilla analog (and not digital) line to OfficeConnect.
Since the connection from the CO to OfficeConnect is also analog, this involves an extra
analog- to-digital conversion, which results in a maximum connection speed of 33.6 Kbps.
However, you can still multi-link these two 33.6 Kbps connections, which is what we did in
out test. Even 33.6 Kbps X2 lines, which amounts to 67.2 Kbps throughput, is still cool
— when you’re using plain old analog lines, that is. We should note that if we
had used our digital T1 lines to call into OfficeConnect, we would have had no difficulty
connecting at 56 Kbps. (During our test, our digital T1 voice channels were being
serviced, so we were forced to use our analog lines.)
The Windows 95 machine we were using was not OSR2 (a service release of Win 95 that
includes patches), so we had to go to Microsoft’s Web site,
where we downloaded the latest version of DUN (Dial-Up Networking), called DUN 1.2b, which
adds multi-linking capabilities to Windows 95 clients. After installing the DUN upgrade,
we installed two 3Com X2 modems into a Windows 95 machine and set up one dial-up
networking connection with the first phone number on the OfficeConnect. Within this same
screen, we then added the second phone number under the Multi-link tab. The second phone
number is listed under "Additional Devices."
We were able to connect on the first line, but we couldn’t get the second line to
dial out and connect. We did some troubleshooting, and we checked out the newsgroups, but
to no avail. We also left a message for 3Com, but we were getting close to deadline, so
weren’t able to discuss the problem with them. We doubt it has anything to do with
3Com’s product. We think it is more likely that something in our Windows 95 machine
is set incorrectly. Unfortunately, the instructions on multi-linking are sketchy, which
makes it difficult to troubleshoot.
ROOM FOR IMPROVEMENT
One problem we noticed was insufficient password length. We had
an ISP password which was over 10 characters long, but the OfficeConnect has a limit of 10
characters. We had to logon to our ISP’s Web site and choose a new, shorter password.
As stated earlier, the documentation should be
improved, particularly when it comes to distinguishing between the Preferred Method and
the Alternative Method of configuration. Also, adding a FAQ sheet or a quick install guide
could be helpful.
Finally, there is a minor bug with the modem answer page. As
previously mentioned, we couldn’t set modem port 2 to answer on one ring. We had to
set the number of rings to "no answer," or a number of rings greater than 1.
CONCLUSION
3Com’s OfficeConnect is an extremely versatile product. It gives small workgroups
high-speed Internet access. It facilitates telecommuting. It enables remote access of
corporate resources. Moreover, OfficeConnect’s capabilities aren’t limited to
data communications between corporate sites. This product can also transmit fax or even
voice using IP telephony.
We were extremely impressed with OfficeConnect’s feature
set. Indeed, we consider OfficeConnect a good, low-cost alternative to ISDN, whether for
Internet connectivity or linking multiple corporate sites. Just think of how complicated
ISDN can be. After you get your local CO’s attention, you wait at least 2-3 weeks for
the technicians to come and install the ISDN lines. Then you have to set up your router
with SPIDs and other ISDN-related bits of information Why deal with the hassle? Take a
quick trip to CompUSA, buy the OfficeConnect Dual Analog Router, and be up and running in
15 minutes, barring any problems with the documentation. (If we hadn’t been confused
by the documentation, we would have enjoyed an extremely easy setup and install.)
One final note: We would like to emphasize that 3Com’s
OfficeConnect is based on EPROM technology, which should simplify firmware upgrades to the
latest ITU 56K standard. |
Internet Telephony Magazine
Click here to read latest issue
CUSTOMER 
Cloud Computing Magazine
Click here to read latest issue
IoT EVOLUTION MAGAZINE
