By John Shireley
Part
of your planning process should include deflating any incorrect or preconceived
notions that your users may have. Despite the commercials with which the
general public has been inundated, simple, powerful remote access just isn't
reality. That's not to say that things aren't improving every day, but you've
got to rely on your ability to plan ahead and to position your users so
that they can optimize the meager tools you are able to provide.
For starters, make
sure that a user's notebook is equipped with an adapter that supports
both Ethernet (you could get lucky!) and a modem, and, as a last resort,
also supports a cellular phone interface. Make sure that the user doesn't
plan to download a 15-MB file 10 minutes before his or her presentation.
Emphasize that he or she should always test connectivity before its
actually needed. Any information that you or your user can obtain in advance
about the available facilities will help you plan your management and
support strategies. Additionally, request to speak with a manager or the
person in charge of the propertys telecommunications services. However,
its not unusual to find that these services have been outsourced.
Make sure that your users obtain all costs up front, including installation,
if they need something other than in-room analog services. Please note
that sometimes "available" doesnt mean "in place,"
and that extra fees may apply.
Another good idea
is to have your users acquire a reliable, removable and portable mass
storage device for transporting large files. Sure, theyd prefer
having a huge hard drives on their notebooks, but those drives wont
help them if the laptops are damaged in transit. Having something that
can be quickly reconnected to a desktop or other laptop will help prevent
a failed notebook disaster. Be sure it uses something universal between
notebooks and desktops, such as a parallel port or USB-enabled drive.
Should a user experience a failure, he or she can quickly move to something
else in an emergency. Additionally, encourage your roving users to take
as many files along with them as possible instead of downloading them
from your network. Make sure they know which types of files are and arent
portable. Many users mistakenly believe that their files can be accessed
only via some kind of network connection (even remotely via modem). They
dont realize that a file can be made portable merely by loading
its parent application locally. This isnt the most elegant approach,
but again, were talking about contingencies and disaster avoidance.
Pretty isnt as important.
Finally, what do
you want to host at your site for them to connect to? If you're directly
connected to the Internet (dedicated 24x7), you'll have ample options
available. If not, you'll need to install a dedicated terminal server
(a requisite if you're going to have a lot of remote and mobile end users),
a modem in a server for direct RAS-style connections, or a modem on the
user's stationary PC for a "remote-control" style solution. We'll discuss
these options as we progress, but you should start thinking about them
now. A good source of useful information can be found at:
Application
Usage and Quality of Service
Is the user going
to need an application that resides on the central network, or will he
or she need occasional access to files, resources and e-mail? Your answers
will determine your bandwidth and latency issues and tell you if youll
require a more sophisticated client/server or thin-client application
approach, or something as simple as a PoP server account with limited
RAS authentication for occasional file down/uploads.
Any kind of interactive
application usage is not a good idea for your mobile users. It can be
done, but its difficult to do well. Some common examples of an interactive
application would include database access, and account entry (any type
of situation where a client is open and actively talking with a server).
This is an area where you must know and understand the specific dynamics
of the expected type of traffic. A well-designed, thin-client technology
really stands out here, but a user that expects to actively edit a large
spreadsheet across an anemic connection is going to be in for a rough
ride. You can find excellent information on this subject at:
Clearly, you cant
plan on consistent QoS (Quality of Service) from a remote, analog, dial-up
user. So many elements are out of your control and you have very few options
available to remedy the problems this type of user is likely to encounter.
Not to mention your having to deal with a client that is only able to
squeeze out a few kilobits of connectivity when the application requires
a very low latency on the pipe or at least several kilobytes of room to
work in. In most cases you'll be dealing with finicky modems, hotel switchboards
and long-distance carriers. This applies to users that access your network
courtesy of the Internet, as well as your direct dialers.
The ideal method
of dealing with these particular issues is to select the best equipment
available that has been tested with your selected ISPs or your own direct
access gear. You can't control the hotel's switchboard or the LD circuits
between you and them, but you can pretest the equipment you're supplying
to your user, choosing the most compatible configuration. Don't always
choose the equipment that connects the fastest; pick the products that
establish the most reliable connections. Perform "endurance" tests, checking
how long a device can remain connected. Fast connection rates are no indicator
of overall performance. Simply achieving the highest data rate possible
isnt the only element you need to consider; faster data rates over
analog circuits are more prone to encountering data errors, and may force
more retraining of the modem. A slower but more consistent connection
will provide better overall performance than one that is faster on connect,
but must continually retrain. Allowing for full autonegotiation is better
than trying to force a high data rate that causes the connection to constantly
hiccup midstream. You also cant trust the initial connection speed
reported by your dial-up client; most only indicate the initial rate.
They dont demonstrate the whole story as your modem retrains itself
into a downward spiral.
Your options significantly
improve, however, with a remote user dialing in from a fixed location,
such as a home office, especially if the user is local. If he or she is
dialing directly into your network, you have some control over the amount
of bandwidth he or she can receive. Since the user is located in one spot,
he or she can choose the connection type instead of accepting the standard
solution (like the mobile remote-access crowd must do). You can have ISDN
lines installed for your "bandwidth-hungry" group (provided
youre able to support that interface with corresponding BRIs or
PRIs feeding your terminal serving equipment and that the service is available
in your area).
Many client/server
applications are designed to work with headroom of 64 Kbps to 128 Kbps,
with space to spare. If youve got the resources to consider thin-client
technology, such as Citrixs Winframe or Microsofts Terminal
Server, and your applications fit into that model, this solution is a
good way to go. Thin clients operate with very little bandwidth and considerably
improve interactivity for remote users. They also provide virtually complete
control over your end users environment if youre able to use
diskless workstations; you simply feed them their desktop, and they have
no way of permanently changing the configuration. An excellent review
of this technology can be found at:
If you prefer that
your users access your network via the Internet, do a little research
before selecting an appropriate ISP. Bigger is not always better in this
case. Ideally, your user should dial into the same ISP that your corporate
bandwidth originates from, thereby alleviating the amount of network (router)
hops that will occur to reach you. If youre both using ISP X,
there should only be a few hops because the connection never actually
goes out onto the Internet: All the traffic is carried on the ISP's internal
backbone straight to you. An additional benefit of routing your remote
users to your network via the Internet is that your internal support will
be reduced. Youll avoid the headaches and costs of having to support
your own private dial-in pool. With no additional lines and no additional
equipment, your existing equipment should be fine, provided that you have
good security.
A final word about
remote-control softwarei.e., software that lets a user dial in (either
via a modem, or via IP) and control a selected host. This approach is
a terrific alternative to thin-client technology because it lets a remote
user completely control a local host machine and have all transactions
occur on the local machine. The software only needs to coordinate screen
updates across the connection, which can typically be done quite nicely,
even over the slowest of connections. Your user can work on bloated applications
from home or on a machine located at the office, and not use the bandwidth
that would have otherwise been required to transport the actual data back
and forth. Only screen updates are required to cross the connection. One
disadvantage is that this is resource-intensive in terms of distributing
workstations. If a user already has two computers, one mobile and one
on your network, then this is a great solution. If they dont, then
youll need to dedicate one for that user. You can see how this would
quickly deplete your budget. Security isnt as much a concern as
it used to be because most products allow for various forms of end-to-end
encryption. Therefore, dont let that stop you from investigating
the feasibility of remote-control software.