There are 2 versions of the networking suite of software for the Mac OS: Classic Networking, and Open Transport. Which is installed will depend on both the version of the Mac OS and the specific hardware in the Mac. The two suites use different control panels, which are briefly explained below.
Classic Networking is the original suite that incorporated built in file sharing and capabilities for using network schemes other than LocalTalk.
The 2 control panels associated with Classic Networking are:
Network: Lets you set which port Appletalk will operate through, printer port or other network (such as Ethernet or Token Ring.)
MacTCP: Lets you set IP parameters, and lets you determine which port IP traffic will be routed to. IP through the printer port is MacIP, tunneled through Appletalk. Requires a server to un-tunnel it.
Special Note: Classic Networking allows for use of BootP, but does not support DHCP.
The 2 control panels associated with Open Transport are:
Appletalk: Lets you set which port Appletalk will operate through; printer port, modem port (Open Transport only) or other networks (such as Ethernet or Token Ring.)
TCP/IP: Lets you set IP parameters, and lets you determine which port IP traffic will be routed through. IP through the printer/modem ports is MacIP, tunneled through Appletalk. Requires a server to un-tunnel it.
Special Note: Open Transport allows for use of DHCP as well as BootP.
Both suites also rely upon different sets of system extensions, but the lists are somewhat extensive, and aren't listed here.
Some Macs must use Classic Networking, and some must use Open Transport. There are quite a few in the middle of the spectrum that can use either one. Hopefully a chart of what's what is forthcoming.
In the meantime, here are some basic guidelines regarding the system requirements for Open Transport vs Classic Networking:
Hardware:On the Macs which can use either, you can switch back and forth between the two without having to re-install the OS. On all such Macs, the OS installer will place a utility called "Network Software Selector" on the hard drive, inside the "Apple Extras" folder.
When it's run, NSS will tell you which suite is currently in use, and allow you to select the other or stay with the current one. After switching, you must restart the Mac for the change to take effect. In most cases, you will need to review the settings in the control panels after such a switch.
Built in Networking - LocalTalk
Note: LocalTalk and AppleTalk are not interchangeable terms. LocalTalk refers to a wiring scheme, AppleTalk refers to a packeting standard. More on AppleTalk later.
All Macs with a Din8 connector as a printer port can handle LocalTalk networking, and adapters can be purchased for some Macs which use the 9 pin serial connector. LocalTalk is built into the hardware of all Din8 Macs and in some of the 9 pin Macs, and is included in Mac OS versions 7.0 and later (System 6.0.8 has limited support as well.)
LocalTalk was originally designed to allow for basic printer and file sharing using AppleTalk (also built into the OS.) As a result, you'lll find a sometimes bizarre mix of connectivity options in printers. Many of Apple's early laser printers are LocalTalk only, some models are serial only, and most modern ones have Ethernet as an additional option. Apple's line of StyleWriter inkjet printers are sometimes LocalTalk capable, and always serial capable.
LocalTalk is a daisy-chain cabling scheme. Each Mac is connected by a junction box which plugs into the printer port (by default - under OT the modem port can also be used.) Each box has 2 ports for connecting the cabling.
The chain does have to be terminated at each end, just like Thin Ethernet. This is accomplished either internally in the box, or by attaching a resistor to the second cabling port on the box (depending on the box style.)
LocalTalk cabling can take more than one form. The two most common are Apple's, which uses Din4 connectors at each end and Din3 connectors in the boxes, and Farallon's PhoneNet, which uses RJ11 connectors. It should be noted that 4 wire RJ11 cable is significantly cheaper than Apple's cables.
The LocalTalk standard provides for speeds of up to 230.4 Kb/s (or about 29 KB/s), but not all Macs are capable of this speed - it depends on the version of the serial controller on the logic board. However, one slower Mac will not cause the entire chain to slow to its speed - only transactions that deal with that particular computer suffer from its speed limitations.
Ethernet
There's not a whole lot to say, as Ethernet is basically Ethernet, no matter the computing platform. Most of the later model Macs have 10 MegaBit Ethernet built onto the logic board. There's usually a 10BaseT port, but occasionally it's just an AAUI port, which requires a separate transciever.
The only other thing to note is that there are quite a few different types of Ethernet cards available for Macs, depending on the slots avaiable on various logic boards. Perhaps one day there will be an exhaustive list of the models MCCSC has in the schools and the cards they can use, but that day isn't today.
Other Networking Schemes
Various companies have made and do make cards for other networking schemes, such as Token Ring and Fiber. Since MCCSC doesn't use these, they won't be discussed (and I'll admit I just don't have a lot of info.)
As mentioned before, AppleTalk and LocalTalk are not interchangeable terms. LocalTalk refers to a specific hardware standard, AppleTalk refers to a packeting standard for data transmission.
AppleTalk Routing
AppleTalk and TCP/IP can be independantly routed through the Mac's available network ports. So, you can have IP traffic heading out through the Ethernet port and AppleTalk traffic through the printer port - or vice versa.
The "AppleTalk / Network" and "MacTCP / TCP/IP" control panels allow you to select where each protocol will be routed. It was designed this way on purpose, so that older resources such as LocalTalk only printers wouldn't become obsolete when Ethernet was introduced, and to allow for greater flexibility. The selections can be changed on the fly, without restarting the Mac.
Since AppleTalk is the protocol used for file sharing and printing services, it's possible to lose access to such resources if the port setting is incorrect. For example, if a Mac can connect to the Internet but not to the building server, it's probably because AppleTalk is being routed through the Printer Port. It is wise to check to see if there's a reason for the current setting, though, such as using a LocalTalk only printer. Such setups aren't all that rare, since the settings can be changed on the fly.
This flexibility also also allows for bridging LocalTalk to another networking scheme through a Macintosh with an appropriate NIC in it, to share a printer for example. For more information, see the "Eratta" section at the bottom of the page.
Protocol Information
AppleTalk datagrams are smaller than most comparable schemes (NetBeui, IPX/SPX, etc), and as a result it tends to be a little 'chatty' if the network's not configured optimally. However, the size differential means that AppleTalk datagrams can be easily stuffed inside just about any other kind of packet without any difficulty. So, AppleTalk runs on all versions of Ethernet, Token Ring, and LocalTalk.
AppleTalk is used primarily for printer and file sharing support, and was designed for use on a small scale. Regular AppleTalk can't be routed across the Internet, for example, as each machine can't be guaranteed a unique ID number. AppleTalk IDs are assigned on a broadcast basis, each time a Mac is started. At startup, the Mac broadcasts a randomly chosen address, and asks the other active machines if it is currently free. If not, it repeats the process until it finds a free address.
It is routable at the LAN level, however. This was introduced in v2 of AppleTalk, specifically because of the progress made in allowing LANs to grow in size and complexity. At the same time, Apple introduced the capability to isolate AppleTalk devices into 'Zones', so that all such devices weren't advertizing themselves to the entire network. Zones don't have to follow physical LAN structure, they can be set up to group devices logically or by almost any criteria.
There are ways to route AppleTalk past the LAN level, involving tunneling AppleTalk packets inside of another protocol, such as TCP/IP. Of course, this requires a dedicated machine to handle the translation process for the incoming and outgoing packets on the destination network.
Apple has recently introduced AppleTalk IP, which uses TCP/IP packets and the standard IP number identification scheme for routing purposes. As a result, you can now share volumes/folders across the internet without complex translation schemes. However, AppleTalk IP is not compatible with all versions of the MacOS and requires specific hardware. For the time being, I don't think it's a really viable option for most of the MCCSC environment.
It is possible to bridge between LocalTalk and other network schemes (Ethernet, Token Ring, etc) as they all use AppleTalk as their core communications protocol. The only difference is the type of packet they're wrapped up in.
There are 2 ways to accomplish this: by using a Mac with appropriate software to handle the packet-repackaging, or by using a dedicated hardware bridge.
Both Apple and a few third party manufacturers produced software to accomplish this. Apple's is called "LocalTalk Bridge," and allows for as many devices to be bridged as a LocalTalk chain can support. The others are normally sold in conjunction with the company's products, and may have limitations on the number of LocalTalk devices they can bridge.
There are certain hardware requirements to run this type of software. Typically, you have to have 2 MB of RAM available, at least a 68020 processor, and (obviously) a NIC of the type you want to bridge LocalTalk to.
There are several hardware bridges on the market as well, with various limitations on the number of LocalTalk devices that can be attached. Most of these are Ethernet bridges, but it's possible some manufacturer is still making Token Ring models as well.
You should keep in mind that any Macs bridged to another network through a LocalTalk connection will still be limited to LocalTalk speeds. Moreover, whichever Mac is carrying the burden of bridging the two networks will take a performance hit. In the case of an older machine like a 68030 Mac, it should probably be dedicated to the task.