Networking over phone lines ....

[drgarytraub]

A physician asked me to look at a scheduler that he is paying to have developed for his large multi-office practice. I looked, was not particularly impressed, and noticed it was written in Access. He knew that I had written a complete program and asked to see my Scheduler. He was so impressed with the far superior capabilities of mine, that he is considering using mine instead. This was really very flattering (and I owe lots of thanks to the help received on this board and to the Alpha 5 team).

One thing that he needs, however, is to network over phone lines. His current program has its data located on a server at his central office. He goes from office to office and dials in from his laptop to the central office. His program works pretty well with this, and at acceptable speed. Does anyone know the best (and hopefully easiest) way to add this ability to my program?

Gary Traub

[Lowell Wardlow]

RE: Networking over phone lines ....

Gary, if what you/he wants is to be able to dial in and run
a program on the host, I would suggest using pcAnywhere.
You simply dial in to the host and run any program as if
you were there. No programming required.

Lowell

[Phil Rolf]

RE: Networking over phone lines ....

But be prepared....Pcanywhere is SSSSLLLLOOOOWWWW, but works like a champ. I find it very reliable.

[Willard]

RE: Networking over phone lines ....

Gary, I am not sure of this but if you are using DSL or cable allyou need is to map the drive. Since the Ip address is stagnate this ais all you have to do. It is still slow but if the data is small, it is within reason.

[JohnZaleski]

RE: Networking over phone lines ....

Gary,
When he dials in to his central Access database, what is he using to dial (PCAnyywhere RACS Citrix Other???). The best way to find out how it works would be to temporarily install your stuff on his central server and test it remotely. If you are doing a lot more with graphics than the Access database, yours could be a lot slower than Access.
John

[Rhett Scott]

RE: Networking over phone lines ....

Hi Gary,

Below Jack mentions mapping a drive over a high speed connection. I have wanted to do this and then use "shadows" to run an application over what would essentially be a "wide area network". Under this arrangement any application would really fly. The key is to get a virtual drive defined that can be used to build the shadows.

Rhett

[csda1]

RE: Networking over phone lines ....

Rhett,

In a non-client/server model of Alpha 5, while network optimization will speed up execution of code and loading of layouts and field rules, it will not be flying in any sense of any word. Any time you access or write a record over a network, it requires a sequence of locking/unlocking of files and records within those files.
These are exclusive operations (meaning that only one user can access the files at a time) while performing this process. While these are individually very short in time, multiplying it times many records being accessed (for a query, report, browse, etc) by each network user, it adds up real quick. Add to that the network delay of these by a wide area network user makes everyone slow down.

The only way to properly access the data over a wide network is to use a thin client (like Citrix or Win 2000 thin client) or a remote access program like PCAnywhere or Netmeeting etc. In these cases you are really just viewing the operation being performed on a Local Area Network (which is much faster) and controlling it remotely.

When the client server model of A5 becomes available, then it will be a whole different story (since the locking is all performed by the server and not the clients).

Regards,

Ira J. Perlow
Computer Systems Design & Associates
[email protected]

[ROBERT SULLIVAN]

RE: Networking over phone lines ....

I agree with IRA.

WAN's (wide area networks) are totally dependent on the speed of the outside lines, whether phones,DSL, CABLE, or Frame relayT1. These are typically a fast as 1.5 mbs(typically people cannot afford the wide band and usually settle for 128-256 kbs) compared to 10 to 100 mbs of LAN's(local area networks).Network optimization works well with 10mbs and better with the 100mbs.
Most modem lines are well under 56kbs.
PCanywhere repsonse times will drive you crazy with anything under 56kbs.

DSL providers must be willing to provide you with a sTatic IP address for you to use PCANYWHERE or network optimization.

I think you should do what has been suggested previously and try the connections. Network optimization will work but don't be supprised if it is not as fast as you hoped in the wan. I would like to know the difference in speed between the access aplication and the alpha application. Keep us posted.


Bob Sullivan
p.s. good luck

[csda1]

RE: Networking over phone lines ....

Hi Bob,

PCanywhere repsonse times will drive you crazy with anything under 56kbs.

DSL providers must be willing to provide you with a sTatic IP address for you to use PCANYWHERE or network optimization.

Sorry, but I have to disagree with the above. PCAnywhere will work ok over a good dialup phone-to-phone connection (33k max) if it is reliable, low noise and get's close to 33k.

Over the internet, I wouldn't try PCAnywhere with anything less than a 50k connection (and this will be painful). If you have faster DSL or cable so that the host is at least 64k sending to the remote you will find the performance acceptable. Obviously, more bandwidth is better. You can speed up PCAnywhere by reducing screen resolution of the host and the color depth to 16 or 256 colors.

You don't need a static IP to use PCAnywhere, although you will at least need to know the 1st 9 numbers of the IP address. The host lists the IP address and there is a way to configure firewalls to pass PCAnywhere.

Regards,

Ira J Perlow
Computer Systems Design & Associates
[email protected]

[ROBERT SULLIVAN]

RE: Networking over phone lines ....

IRA

The modem issue may be related to geographical area. I live in Daytona Beach. The phone lines here are not what you would expect. I have had "at Times" very poor response times and at other times very decent response times. None of the times however are close to being on site. If an operation takes 10 seconds on site the pcanywhere can expand that easily to 20 seconds. We do not use high resolution or high color content screens.

If "your host provides" means the DSL hosting service provides the IP address then doesn't that mean they are providing you with the static addresses.

[csda1]

RE: Networking over phone lines ....

Bob,

Phone-to-phone are ok if you get roughly 28k to 33k connections. If you don't, or are subject to line noise, then you will get bad PCAnywhere response.

On the internet, it is a whole different story. There, it has a lot to do with your ISP (and delays in packet processing), the host's upload speed, and the delays in the internet. A dynamic IP only means that you get an IP address assigned to you when you log onto the internet. While you are connected, the IP address does not change.

You can get the host's IP address by using Window's winipcfg or one of the many programs available as shareware/freeware to return this value. Then you just have to let the remote know that value. Some of these shareware programs will post this value to a web page just for this purpose (or you can ask someone at the host's location).

Regards,

Ira J. Perlow
Computer Systems Design & Associates
[email protected]

[drgarytraub]

RE: Networking over phone lines ....

Thanks for all the discussion on this topic. It certainly sounds like PC Anywhere is the easiest way to go. But does that mean that only one remote user can access the server at one time? And does that also mean that the server must be dedicated, i.e., noone else can use it while it is being accessed from a remote site(s)?

[csda1]

RE: Networking over phone lines ....

Gary,

Basically, PCAnywhere and similar are used on a client machine that is on the LAN. The remote just controls the local client remotely. Citrix and Thin Clients allow multiple dial-ins doing essentially the same concept, except they are closer (meaning faster) to the server (if not actually the server too). In that case, one thin client server can allow many access remotely as if they are on a local virtual windows system.

Regards,

Ira J. Perlow
Computer Systems Design & Associates
[email protected]

[drgarytraub]

RE: Networking over phone lines ....

Thanks Ira ... I think I understand.

Gary