This a modified version of Merit's MacPPP Link Access Protocol module. In plain English, it allows you to establish a dial-up PPP connection with a TCP/IP network like the Internet. It differs from the official Merit MacPPP 2.0.1 release in that it provides the following additional features:
• Supports DTE rates of 115Kbps and 230Kbps on Macs w/GeoPort serial architecture.
This can be useful for folks with 28.8 modems or serial ISDN Terminal Adapters.
• Compatible with Apple's new Open Transport TCP/IP replacement for MacTCP.
See below for OT configuration instructions.
• Compatible with PSI's implementation of ISDN PPP service courtesy of John Stephen.
• Timing change for modems that can't respond to commands quickly. Also by John Stephen.
• Displays modem connect info in MacPPP Status dialog courtesy of Steve Brecher.
This in not an official Merit release of MacPPP. The folks at Merit wrote it, I just released a modified version. The funny version number is supposed to indicate new features and has my initials appended to differentiate it from anybody else's modified MacPPP. In retrospect I probably shouldn't have changed the number from 2.0.1 but the damage was done in the previous release. This will probably be the last SD labeled release as a few of us that have modified versions of MacPPP out are trying to create a unified release (as you can see from the feature list above this version had a couple of additional chefs). The first release of this unified version is being released by the Belgian MacBel User Group as MacPPP 2.2.0 and should be available on an InfoMac or UMich mirror near you soon.
Is a 115K or 230K DTE rate really going to be faster than 57.6K?
It depends on the data being transferred and the type of connection you have.
For modems, the V.42bis data compression standard is theoretically capable of 4:1 compression. Therefore you'd want a 115Kbps DTE rate to fill a 28.8Kbps V.34 link w/V.42bis compression. In the real world most data doesn't usually compress better than 2:1 so a DTE rate of 57.6K is usually sufficient. On the other hand I've seen better than 8000 bytes/sec using Fetch to ftp a highly compressible text file (400K of repeating 'abcdef') over a 24K V.34 link. Using the Electronic Frontier Foundation's "Big Dummy's Guide to the Internet" as a test file I've gotten in the neighborhood of 6200 bytes/sec. Keep in mind that the port speed has no bearing on the connect rate of your modem. A 28.8K connection requires very clear phone lines at each end. Connect rates of 26.4K or 24K are much more common.
The only modem I know of that supports a DTE rate of 230Kbps is the Hayes Optima 288. They use a modified version of the V.42bis compression routine that's theoretically capable of 8:1 compression (as opposed to normal V.42bis' 4:1 max). Unfortunately I don't have one so I can't say what sort of throughput my test files would have at the 230K DTE rate.
With a serial ISDN Terminal Adapter (aka an ISDN modem) you get a 64Kbps link with one channel or a 128Kbps link with two 'bonded' channels. Compression would make throughput even faster. What port speed you should use is dependent on the ISDN equipment you are using. I've never actually tried an ISDN connection with this software (anyone want to donate the equipment so I can? :-) ) but have had reports from several users that it works for them.
Note - If your modem or ISDN TA doesn't list support for a 115K or 230K DTE rate in their documentation, don't try to use it. One of the most common problem reports I get is folks trying to use the faster rates on equipment that doesn't support it.
Caveats
The changes to support the higher DTE rates make use of an undocumented and unsupported serial driver call as well as some direct manipulation of the Serial Controller Chip. This has been working for months for lots of folks but there are no guarantees.
What do I need to use it?
You need a Mac with the GeoPort serial architecture and a 28.8 modem or ISDN Terminal Adapter attached to the built-in Modem or Printer port. The increased interrupt load for the higher rates is too much for non-serial DMA Macs so I'd strongly recommend against using it on one although I don't currently check the Mac type (and as near as I can tell it's impossible to check to see if the serial ports are of the GeoPort variety). If you insist on trying it on a IIfx or Quadra 900/950 you must make sure that you have set the serial ports to 'compatible' mode using the Serial Switch Control Panel. If you don't, you'll crash your Mac when you try to connect. Since I already said you shouldn't be using this software on one of these machines I don't consider this a bug so consider yourself warned.
Of course if your dialup PPP provider isn't using 28.8 modems or ISDN service with a 115K or 230K DTE rate on their end you won't see any difference. That part I can't help you with. :-)
Does it make a GeoPort Telecom Adapter go faster?
No, it does work with a GeoPort Telecom Adapter (TCA) however. Why doesn't it make the TCA go faster? Because the TCA pod isn't really a modem. It's just the hardware required to connect your Mac to the phone lines or POTS (Plain Old Telephone Service). The rest of the modem functions are implemented inside your Mac. Apple may implement a V.34 version of the Express Modem software but I wouldn't hold my breath waiting for it. I wouldn't recommend it on the PowerMac either as the current V.32bis implementation of the software seems to be good for approximately a 30% slowdown on a 6100/60AV. Eventually Apple is supposed to release a GeoPort ISDN Adapter but I have no idea when or if this version of MacPPP 2.1.1SD will work with it.
How do I use it?
If you aren't sure how to install MacPPP, see the accompanying 'Installing MacPPP' document. Once you have installed MacPPP 2.1.1SD, open the Config PPP Control Panel and hit the Config... button. Select 115K or 230K from the Port Speed popup menu if your communications equipment supports it. That's it. You should now be able to use a port speed that allows the maximum possible throughput of your equipment. If you selected a port other than the Modem or Printer ports you'll get an error Alert when trying to connect at 115K or 230K stating that the higher rates aren't supported for other ports and the rate will be changed to 57.6K.
Using MacPPP 2.1.1SD with Open Transport
Warning: Open Transport 1.0 has some problems with MacPPP's automatic connection mode. While the problem normally shows up as a failure to find a Domain Name Server it's possible that OT 1.0 will crash while MacPPP is automatically opening a connection. Until OT 1.0.1 is released you should open all PPP sessions manually by using the Open button in the Config PPP control panel. When you close a PPP session use the Hard Close button so that MacPPP won't automatically re-connect.
Here are some guidelines for using MacPPP 2.1.1SD under Open Transport. The settings discussed below are found in OT's TCP/IP Control Panel:
1) Select Connect via MacPPP.
2) Select Manually from the Configure menu.
3) Leave the IP Address field blank (see note below for additional info).
4) Fill in the Domain name field with the root name of your domain (i.e. mycompany.com or myschool.edu).
5) Leave the Subnet mask field blank unless you require a special mask.
6) Fill in the Router address and Name Server address fields with the dot addresses (i.e. 128.1.1.1) of the respective machines. The Router machine may also be referred to as the Gateway machine.
Note: Normally the IP address of your machine is assigned during the PPP connection establishment phase and MacPPP extracts this info and makes it available to Open Transport. If your PPP server doesn't provide this information as part of the establishment phase (possible if you have a static IP address) you may have to manually configure MacPPP for your local IP address. This is done using the IPCP Options dialog when configuring a PPP server in the Config PPP control panel. Turn off the Want and Will checkboxes for the Local IP address box and fill in your static IP address for the local value. Before you try this, as it is a rare requirement, make sure that just leaving the IP Address field blank doesn't work for you.
Why does MacPPP dial when my Mac starts up?
MacPPP tries to open a connection whenever it sees TCP/IP packets unless the Hard Close command was used to terminate a PPP session. This isn't remembered on restart however. There are several extensions that send TCP/IP packets when they load at boot time so this is why you get connection attempts during startup. The extensions (or the programs that install them) that I know of that do this are: Apple's SNMP agent software installed as part of the full MacTCP install, Farallon's Timbuktu Pro, ON Technology's Meeting Maker XP, and a shareware control panel called Network Time (I'm not sure of this name as I haven't actually seen this one). See if there's a configuration option to turn off this functionality at startup or remove the offending extension (anyone ever use the SNMP software?). Another extension that will cause connection attempts every time an application quits is ZapTCP. Since this extension is intended solely as a debugging aid for folks writing apps using TCP/IP packets I highly recommend removing it unless you know you need it.
Known Problems with this release of MacPPP 2.1.1SD
There are known problems with Open Transport 1.0 and PPP sessions that are opened automatically. See the section above on using MacPPP 2.1.1SD with Open Transport. As noted there, the 1.0.1 release of Open Transport should fix this problem.
Apparently the software for the Axion serial port switching device makes the test for the internal serial ports fail and revert back to a DTE rate of 57.6K. I don't have one of these critters so it's kinda hard to figure out a workaround other than turning off their software.
The extension 'ASFU Fixer' apparently reverts the serial driver to a pre-DMA version thereby breaking support for 115K and 230K port speeds. As far as I know this extension is only required when using printer drivers from GDT Softworks. Try asking them why they don't fix their drivers instead of mucking with Apple's serial driver.
It seems Wacom has a similar 'fix' for their serial port connected graphics tablets. I don't know what the name of the offending extension is however.
Using the Terminal Window mode on an 840AV running System 7.1 and MacTCP with Display Enabler 1.2 installed will crash. Removing the Display Enabler extension solves the problem. This problem might also exist on other Macs but I don't know for sure. If you really want the functionality of the Display Enabler and you have to use the Terminal Window mode I suggest you upgrade to System 7.5 which has the functionality built-in but not the problem.
If you try to establish a connection with the Terminal Window mode and hit the OK button without actually starting a PPP session MacPPP will get confused and you'll have to restart your Mac before you can try connecting again. Clicking the Cancel button works as you'd expect and is what you should use to cancel a connection attempt anyway.
Thanks to Bill Coleman of Hayes for reminding me to think async instead of sync when programming the SCC for the higher rates. I've been doing code for 13-bit sync serial data for so long I forgot what async was. :-)
Thanks to John Stephen <john_stephen@pop3.interramp.com> for the command rate timing and PSI ISDN compatibility mods.
Thanks to Steve Brecher <sbrecher@connectus.com> for the connect rate info display mods.
Thanks to Larry J. Blunk (ljb@merit.edu> and the rest of the MacPPP programmers for making the source code to 2.0.1 available. Remember, they wrote it, I/we just modified it.
Version History
2.1.1SD - 06/24/95
• Public release of MacPPP 2.1.1SD
2.1.1SDb3 - 06/23/95 - A not too public Beta
• No change in the version number but this read me was revised to document a problem with Open Transport 1.0 and automatically opened PPP sessions.
2.1.1SDb3 - 06/22/95 - A not too public Beta
• One more minor tweak to the startup delay code to give internal PowerBook modems a chance to power up.
• Revised section of this Read Me dealing with OT configuration and to explain why MacPPP opens connections at startup.
2.1.1SDb2 - 06/17/95 - A not too public Beta
• Several minor changes in the code trying to work around the problem with the Display Enabler extension but no luck. See the warning above in 'Known Problems'.
2.1.1SDb1 - 06/16/95 - A not too public Beta
• Now Open Transport compatible.
• Incorporates John Stephen's mods for slowing the command timing down for the Motorola BitSurfr ISDN modem and setting the control character escape mask for compatibility for PSI's PPP service.
• Incorporates Steve Brecher's mods to display modem connect rate info.
• Fixes long standing problem with rates other than 115K and 230K occasionally not working.
2.1SD - 12/11/94
First public release.
As always, revised this Read Me.
2.1SDb3 - 12/10/94
Third semi-public beta.
Due to popular demand (from Lyman Green) I have now updated the Config PPP Control Panel to show the 115K and 230K rates in the Port Speed popup.
Revised this Read Me once again.
2.1SDb2 - 12/08/94
Second semi-public beta.
Oops - left in a modified version of the modem init code that occasionally caused timeouts when trying to establish communications with the modem.
Cleaned up and expanded this Read Me.
2.1SDb1 - 12/06/94
First semi-public beta
Cleaned up the code somewhat and actually check for a suitable serial driver before making the calls.
2.1SDa3 - July 1994
Never publicly released.
Made sure selected port was modem or printer.
2.1SDa1 - July 1994
Never publicly released.
First build.
Comments or Questions?
You can e-mail me at sdagley@iu.net (Note this is a new address)
