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Internet Sharing Solutions (Part 1)
By Thiravudh Khoman

One of the more notable features of the new Windows 98 Release 2 is its so-called "Internet Connection Sharing" which allows a Windows 98 PC to share its modem and internet connection with other PC's on a network.

As interesting as this may sound, the feature is far from ground-breaking. Personally, I've tried or used a half dozen such solutions in the past year and I believe dozens more exist out there. As I'm currently using two such solutions - one at work, another at home - I thought a review (or two) might be useful.

Internet sharing of this type is usually implemented by either adding a piece of hardware to the network or by running specialized software on a host computer. While my experiences and therefore my examples will be rooted in the Windows 9x/NT world, no doubt similar hosting solutions exist on other platforms as well. For example, under Linux you can do something similar via IP Masquerading or by using a SOCKS proxy server.


At work, we use a hardware device called a WebRamp model 300e (figure 1) which is manufactured by Ramp Networks (https://www.rampnet.com). The WebRamp is an example of a hardware solution which doesn't rely on any particular computer platform or operating system. But it is hardly the only one. Similar but cheaper Taiwanese products also exist and many of the big networking companies have offerings as well.


The WebRamp is about the size of 4 VHS videotapes stacked 2 by 2. It contains a 4-port 10Base-T hub which can be used as a standalone hub to connect 4 client workstations. It can also be connected to an existing 10Base-T network by using one of the ports as an "uplink" port (which is how we have it set up).

Modems are connected directly to the WebRamp and not to any particular workstation. The WebRamp 300e supports up to 3 external modems of up to 56kbps each. Other WebRamp models exist which support fewer modems, which come with pre-installed internal modems, or which are designed for ISDN connections. At work, we've installed two external USRobotics Sportster 56kbps modems, leaving open the option of a third modem if and when it is needed. The modems are connected to separate telephone lines - direct lines in our case, although it's also possible to dial out through a PABX.

When two or more modems are used, the WebRamp engages a protocol called "COLT" to efficiently manage the bandwidth of each connection. While it is customary for each modem to dial into the same ISP, this is not an absolute requirement and three modems could in fact dial three different ISP's. This provides a degree of fault tolerance in case one ISP goes down. Both of our modems though, dial the same ISP.

For enhanced performance, if the ISP supports something called "Multilink PPP" the bandwidth of each connection can be spliced together to form a single large "pipe". This provides the best performance possible, but not all ISP's support this protocol. and even if they do, special arrangements sometimes need to be made to use it since all of the modems will dial into a single account, unlike COLT which dials into separate accounts.

The attached modems can be configured to start up simultaneously when the WebRamp is initialized or to be individually "dialed on demand" when the existing modems become overloaded. Similarly, modems can be disconnected after preset periods of inactivity or left connected perpetually. In Thailand, where we have a flat rate per call, but pay ISP fees by the minute, one has to work out a compromise between telephone costs versus ISP costs. This of course differs from the U.S. where one can obtain flat rates for both local telephone and ISP service.

All workstations that access the WebRamp must use the TCP/IP protocol. In support of this, the WebRamp can act as a "DHCP server" to distribute IP addresses to client workstations. If a DHCP server already exists on the network or if static IP addresses are already being used, this can be disabled (only one DHCP server can operate on each network), although gateway and DNS values must be manually set at each PC. When operating, the WebRamp will have a real IP address dynamically assigned by the ISP at the modem interface. At its LAN interface, however, the WebRamp must be pre-assigned a static IP address. We chose to use non-routable IP addresses in the 192.168.x.x range for both the WebRamp and the client workstations. This essentially sets up a firewall which prevents outsiders from getting through to the local network.


As I mentioned earlier, this is a hardware solution and no WebRamp-specific software needs to be installed on any of the workstations. Still, the WebRamp itself needs to be configured and this is done by running a Java applet (figure 2) from a web browser. Typical settings include: modem type/speed/init string, ISP telephone number/login/password, connect/disconnect thresholds, WebRamp IP address, DHCP IP address ranges, etc. Most of the default settings work fine, so not every esoteric setting needs to be tinkered with. These settings are saved in the WebRamp's non-volatile memory and not on any workstation.

All workstations that access the WebRamp must have a LAN/network card installed and be connected to the local network. In addition, they must have TCP/IP bound to the LAN card (not just to Dial-up Networking). Other network protocols such as IPX or NetBEUI may also be present, but they're not used by the WebRamp. While the procedure for installing a LAN card and the network components under Windows 9x/NT is not extremely complicated, it can be somewhat daunting for beginners. The WebRamp comes with some simplified client installation programs for Windows PC's, but it's not absolutely necessary that you use these if you're used to adjusting network settings under the Control Panel.

So how difficult is it really to setup the WebRamp? Frankly speaking, I got stuck a bit the first time I worked on it (my problem was due to an incorrectly set dip switch). It should be noted, though, that I have a fair amount of experience setting up networks, configuring LAN cards, and already had a production network up and running already. This only left me with the problem of figuring out TCP/IP. Still, the documentation is complete and well written, there's a fair amount of supplementary reading on RampNet's website if this isn't enough. If you read these carefully and don't set an arbitrary time limit to get everything up and running, I'd urge a do-it-yourself approach. In our case, I negotiated a lower price for our WebRamp, as I planned to do the installation and configuration myself. But I also left open the option of calling in the experts if I got stuck (at additional cost, of course).

ISP Support

Perhaps I'm being a bit harsh, but it's my guess that most ISP's hate these kinds of devices. If you're a corporate entity with little money to spend, I think ISP's prefer that your users sign up for individual accounts. On the other hand, if you have some spending money, they'd probably like you to get a dedicated line, which can be horrendously expensive for decent bandwidth. Ask them upfront what kind of support/package they have for such devices as WebRamps and many will respond that they have none or that you are not allowed to use such things with their internet connections.

Personally, I find this to be short-sighted. A dedicated line is a difficult to justify luxury these days. In actual fact, you don't need their permission at all - you could punch in the login name and password of a "phone-card" type ISP account into the WebRamp and it would work perfectly well, all the while remaining anonymous. The only problem is that you'd need to replace the accounts often as they would get used up quickly. Also, to the ISP, the WebRamp looks no different than any other dial-up computer.

Still, a number of ISP's do support this. Loxinfo has something called "WebSharing" for use with WebRamp-like devices. Loxinfo's connect charges are Baht 32,000 for the first 1,500 hours or Baht 56,000 for the first 3,000 hours. To this must be added an annual maintenance fee of Baht 12,000 per year. Assuming that you access the internet an average of 5 hours per day, 5 days a week (107 hours/month), this will cost you Baht 3,000 per month for the cheapest rate. Increase the usage to 10 hours/day (214 hours/month) and it will cost you Baht 5,000. For more information, check out: https://www.loxinfo.co.th/loxinfos/htm/webshare.htm.

Meanwhile, Asia Infonet has something called "Virtual Domain Service", also for WebRamp-like devices. Asianet charges Baht 10,000 as a start-up fee, Baht 5,000 as an installation fee, and Baht 6,000 per month for usage, with the proviso that data transfers be less than 400mb per month. Assuming that the starting fees are spread out over one year, the monthly costs would be Baht 7,250 - that is, as long as data transfers don't exceed 400mb/month. Be VERY wary of this limit as your costs could easily skyrocket out of control. For more information, check out: https://www.asianet.co.th/ai/english/corporate_service/index.htm.

While these prices are fairly high compared to individual accounts, they're 10 times cheaper than dedicated 64kbps lines which cost Baht 54,000 at start-up and Baht 54,000 per month thereafter at Asianet (Baht 60,000 and Baht 60,000 at Loxinfo). Granted, there are pros and cons to each, but if you're on a limited budget, it's nice to have a lower cost (but not lower performance) option.

Both Asianet and Loxinfo are what I consider "Tier 1" ISP's. They have good 56kbps modem support (at least in Bangkok) and they have decent-sized "pipes" to both the intra-Thailand network and to the U.S., where most web browsing would be destined. Before choosing an ISP - any ISP and for whatever reason - I highly recommend that you first peruse the Thailand Connectivities Map at https://www.nectec.or.th/internet/map/ and study how well an ISP is connected.

As it turns out, I opted against both Loxinfo and Asianet. We're a small educational institution and since we also offer night classes, our working hours can sometimes run to 10-12 hours per day, 6-7 days a week. All our staff are internet savvy and as a result, our monthly usage, while probably not terribly high in volume, extends for long hours. In light of the above, Loxinfo would probably have costed us over Baht 6,000 per month. Meanwhile, Asianet's 400mb/month data transfer limit, while difficult to gauge, left no doubt in my mind that we would incur some undefinable excess charges.

Granted, I could have tried to reduce usage by limting internet access to certain hours or to certain PC's, but I was strongly opposed to this. After all, the objective of internet sharing is to expand the use of the internet, not to limit it.

In the final analysis, I chose to use Data Line Thai (DLT), a lesser known "Tier 2" ISP. DLT offered a package which allowed unlimited access at an average price of Baht 4,900 per month (Baht 5,000 start-up, Baht 62,700 Baht for 12 months plus 2 free months). This account, however, could only be used with one modem. For our second modem, we signed up for a regular DLT account, but then I adjusted the WebRamp to call up the second modem less often. For more information on DLT, check out https://www.linethai.co.th/pc-price.htm.

While DLT's services are affordable, they nonetheless represent some serious compromises. First of all, DLT has no 56kbps modem access. Secondly, if you were to look at the Thailand Connectivities Chart, you'll see that DLT's connections to the intra-Thailand network via the National Internet Exchange (NIX) and the Public Internet Exchange (PIE) are quite slow (64kbps and 128kbps respectively). Thirdly, DLT has no dedicated line to the U.S., but instead makes use of the Communications Authority of Thailand's International Internet Gateway (IIG), and does so at only 192kbps.

Clearly, an "either-or" decision was made, and I opted for limiting my costs at the expense of some performance. In the process, I've bought 7-14 months in which to study our usage patterns. In any case, this isn't a permanent arrangement - when our DLT contract expires and we decide we want and can afford greater internet speeds, we have the option of switching to a different ISP.


Earlier on, I mentioned that the WebRamp was not dependent on any particular computer platform or operating system. Tests were run with Pentium I/II/Celeron Windows 95/98 PC's and also with a Pentium I PC running RedHat Linux v5.2. Standard internet apps such as Netscape Navigator/Communicator, Internet Explorer, Eudora, ICQ, and FTP were tested and no problems of any kind were encountered.

Performance and Benefits

The biggest question, of course, is how well the WebRamp performs. Before I started using DLT's service, I ran a one week test with one of the aforementioned ISP's to get a feel for how the system would run in a best-case scenario. Not surprisingly, some slowdown could be felt when I switched over to DLT (especially during peak times), but nonetheless, the system was - and still is - very useable.

POP email, for example, takes less time going through the WebRamp than it does for a standalone modem to dial an ISP (even if you're lucky enough to get through on the first dial). This is true even during peak hours. As for web-based mail such as HotMail and all around web browsing, peak hours can be a bit sluggish. But then no one ever accused HotMail of being fast. During non-peak hours, web browsing speed is acceptable.

Despite some of the shortcomings, I believe this is a reasonable price to pay for flexibility. All our computers are networked and all have Netscape and/or Internet Explorer installed on them. Thus anyone - be it staff, students, parents waiting for their children, visitors, etc. - can use our computers to access the web; for free I might add, since we've already capped our costs. Being able to access the internet this way also saves us from having to buy modems for each PC, having to re-wire/extend telephone lines, and most important, frees up all of our regular voice lines so that customers can call in.

Using the WebRamp also changes the way we work. With a dial-up connection, your work becomes focused on a single-task. You dial to check email or to search for information, and then you're under pressure to disconnect as quickly as possible in order to save ISP costs. Forget to do something and you have to redial. This article is a good example of this. During its writing, I had to check for information on the web numerous times. With the WebRamp I could have both Word and Netscape resident and switch back and forth between the two without incurring any dial-up costs. But alas, this article was written at home where I was forced to dial many times up to retrieve information.

The only thing I would avoid doing with the WebRamp is to download large files. Although this is partly due to user congestion on the WebRamp, it is more due to DLT's slow link to the IIG gateway and to the U.S. where most of my downloads come from. At home, I use Internet Thailand as my ISP, and frankly, I'm spoiled by their fat pipe to the U.S. Thus, I tend to download at home and bring the required files to work.

The only other time when the WebRamp is slow is when all of the modems have disconnected due to inactivity. In such cases, the WebRamp needs to redial and go through the user/password verification process before it can service an internet request. This can take up to a minute and can sometimes cause a user's internet app to time-out. DLT apparently disconnects the telephone the line when it senses that the line has been inactive for certain period of time. Although the WebRamp has no way to "tickle" the line to keep it alive, PC-based sofware does exist to do this.

It should be noted that we managed to achieve decent speeds by making use of DLT's proxy server (for web browsing) and SMTP server (for email). While DLT's proxy server seems to be smaller than that of some Tier 1 ISP's, it most certainly helps. Because of this, commonly accessed sites such as Yahoo! and even HotMail, load fairly quickly. As for email, although none of us have our POP mailboxes at DLT, we use DLT's SMTP server to send our outgoing mail, which saves us a hop, skip and a jump.

Finally ...

If you'd like to see/feel how a WebRamp works in action, contact Multimedia Technology (https://www.multimedia.co.th), which is where we bought our WebRamp. They use a WebRamp in-house which is connected via a leased line.

Another possible vendor is iMart. Their previous location at Ploenchit Center (now closed) had a WebRamp with three dial-up modems to rent internet access to walk-in users. They have since consolidated their stores at Panthip Plaza, which may or may not still have the WebRamp up for public use. Nonetheless, they do sell the WebRamp, although the model I've seen on display is an outdated Model M3.

The WebRamp is not an inexpensive piece of equipment. Expect to spend Baht 30,000 or so for the device, plus several thousand more Baht for installation and the modems. However, this should be considered a long term investment. The system scales quite well and compared to the costs of a 64kbps leased line, is dirt cheap. With all three modems operating At 56kbps and a "fast" ISP, the system has enough muscle to provide internet access for dozens of users.

In Part 2, I'll discuss another internet sharing solution, one which I use at home. This one is implemented using software only and is considerably cheaper (like free!).

Copyright © 1998-2000, Thiravudh Khoman