Protocol Information
SciNet \ AppleTalk \ NFS \ TCP/IP

• Introduction to SciNet Profile
• SciNet Profile Specifications
• Introduction to SciNet Span
• SciNet Span Specifications
• SciNet MAC Functional Description
• SciNet Performance
  
• AppleTalk
• NFS
• tcp/ip

  see also Ripro Server Maximum File Size

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Introduction to SciNet Profile

SciNet Profile is a Macintosh application that lets you manage files on any station on your SciNet network. At present, Whisper workstations, Star workstations, RS/6000, and Macintoshes can be SciNet stations (with the appropriate hardware and software). You can search for, copy, rename, and delete files on any SciNet staion by using simple and intuitive Macintosh-style clicking and dragging operations.

Using SciNet Profile, you can:

• Copy files between any two stations on the SciNet network by clicking and dragging. The files are copied quickly because the advanced SciNet network protocol is used.
• Search for files by name, type, creation date and other criteria on a particular station or on all stations on your SciNet network.
• Get information (such as the size or creation date) about any file on any station on your SciNet network.
• Rename files on any SciNet station.
• Delete files on any SciNet station by using your desktop Trash icon.

SciNet Profile Specifications

Introduction to SciNet Span

SciNet Span is a Macintosh computer application that provides a link between the desktop and Scitex Response systems. Using SciNet Span on a networked Macintosh workstation, you can perform production tasks such as translating and sending files to a Scitex production system.

SciNet Span enables you to:

• Receive and send files from a Scitex production system.
• Display Scitex and Macintosh images.
• Translate files between Macintosh and Scitex file formats.
• Execute scripts created by Scitex Formats XTension for file translation and degrade creation.

SciNet Span also supports automatic picture replacement (Scitex APR). Scitex APR is a PostScript production workflow designed to automate the substitution of high-resolution Scitex images for low-resolution position images during production.

Scinet Span Specifications

SciNet MAC Functional Description

SciNet Mac provides SciNet based applications with an infrastructure that is fully compatible with all other SciNet stations like Whisper ,PS/2 and RS6000 based stations. Since that infrastructure is based on the PTOP protocol that hides the underlying link from all the upper layers, the functionality of all applications is exactly the same independent of these links. Of course, when moving to faster links, like FDDI, performance is improved considerably.

SciNet Components

• SciNet Boards
• Program to Program - PTOP
• Remote File Access - RFA
• File Transfer
• Static Configuration
• Dynamic Configuration
• File Access Security

LANC (Ethernet) Board

Scitex LANC board is a high performance adapter running standard Ethernet protocols. In addition to supporting AppleTalk, like other off-the-shelf adapters, it runs the transport protocol on board. By doing so, it relieves the Mac CPU from most of the communications load. Currently the LANC board runs standard OSI Transport protocol (TP4).

The LANC board is equipped with a 386 CPU. It supports both AUI and BNC attachments to the network. The AUI can be used for 10Base5 (Thick Ethernet) or 10BaseT (Twisted Pair) connections. The BNC is used for connecting 10Base2 (Thin Ethernet) with no need for an external transceiver.

Program to Program - PTOP

Program to Program (PTOP) protocols provide the lower layers of SciNet infrastructure. PTOP hides the complexity of communications from the upper layers of SciNet and the applications using PTOP directly. PTOP provides its users with a set of API's that are independent of the underlying links.

PTOP API's enable loading processes on remote stations, maintain communications sessions between local and remote processes and exchange data between these processes.

Remote File Access - RFA

Remote File Access (RFA) consists of a set of API's, servers and network loadable servers. The API's enable Mac applications access files and directories located on devices (disks, opticals, etc.) belonging to other stations. RFA Servers let applications running on remote stations access files located on devices belonging to the local station. RFA uses PTOP to communicate between its processes.

File Transfer

File Transfer consists of a set of API's and network loadable modules used for copying files to and from the Mac and other SciNet stations. Each File Transfer involves a file being copied (source) and a target (destination) describing where the file is to be copied to. SciNet File Transfer supports copying of files where the source, the destination, both or none of them reside on the Mac. We refer to the copying of files where neither the source nor the destination reside on the initiating Mac as Third Party Copy.

In Third Party Copy the copying is done locally on a remote station or between two remote stations without moving the data via the initiating Mac. This off loads the Mac from handling the data and avoids creating unnecessary loads on the network. Only error messages and progress indications are delivered to the Mac.

Static Configuration

Each Mac can belong to an Ethernet subnetwork, to a FDDI subnetwork, or to both simultaneously. SciNet user has to configure his SciNet network on each Mac functioning as a Client or Server on that network. To do so, the user has to provide some information on the network.

The static configuration information is entered via the SciNet Configuration control panel located in the Control Panels folder. That information consists of a Station Name that identifies the Mac on the network, and for each subnetwork a Subnetwork Name and Link Type. Each subnetwork is attached to a communications adapter servicing the selected link type.

The user can select whether to configure its Mac to function as a server on SciNet. In that case the user has to add information required for maintaining file access security.

Dynamic Configuration

Most of the information about SciNet stations and subnetworks is acquired dynamically by what is referred to as the Dynamic Configuration. The SciNet Mac user does not have to identify the stations present on the subnetworks and certainly there is no need to specify anything about their devices and subnetworks. That information is updated constantly by the SciNet infrastructure. All SciNet stations attached to the Ethernet or FDDI subnetworks cooperate in the Dynamic Configuration process.

In addition to that, Dynamic Configuration information gathered from the remote SciNet stations enable efficient selection of subnetworks while Third Party copying is performed.

File Access Security

Whenever the Mac functions as a server on SciNet, its devices are protected by security mechanisms that are similar to those provided by AppleShare and actually make use of the tools provided by Apple for that purpose. The access rights to folders and files as specified for AppleShare users are strictly followed by SciNet with no need to reenter the same information.

SciNet Performance

The following tables describes the performance when copying files (disk to disk) between a Mac client and the other SciNet stations. Performance is in KBytes/Sec

AppleTalk

See AppleTalk Configuration on the Ripro Server

Technical Note: SciNet Span & AppleTalk Support on the MAC

AppleTalk is a set of specifications that describe how to connect Apple Macintosh computers, printers and other resources or computers into a communications network. AppleTalk is the architecture that defines a set of protocols used by devices to communicate over the network. Networking with the Macintosh is extremely simple because networking functions are built directly into the Macintosh. Originally, AppleTalk was designed to use the LocalTalk cabling system, but AppleTalk now supports Ethernet and token ring topologies. AppleTalk was also designed for small local workgroups, and so its performance is not adequate for large local area networks (LANs) and wide area networks (WANs), although some improvements have been made for WAN connections.

The LocalTalk cabling system consists of a set of simple connectors that attach to Macintosh systems and provide plug attachements for LocalTalk cable or telephone wire. Transmission rates are a relatively slow 230.4 Kbits / sec, but the total installation cost is low since network adapter cards and workstation software are not required. LocalTalk was originally called AppleTalk, but Apple changed the name in 1989 to LocalTalk and now refers to the networking protocols as AppleTalk. Organizations that need higher-speed networks can install EtherTalk (Ethernet) or TolkenTalk (token ring) network segments. Special adapters and cabling systems are required for these networks.

AppleShare is a centralized file-sharing system that runs on top of AppleTalk on a Macintosh system that has been dedicated for server use. Other Macintosh systems access AppleShare servers through the AppleShare Client module. Services provided by AppleShare include file sharing, printer sharing, and electronic-mail handling. Additional modules such as management systems are available.

With the advent of the Macintosh System 7 operating system, peer-to-peer (distributed) file sharing became available in the AppleTalk environment, whether an AppleShare server is available or not. A user can share files with other users by designating which files to share and access files on other systems that have been shared. However, the file-sharing features in System 7 lack security and are somewhat deficient.

AppleTalk Basic Operation

Devices attached to AppleTalk networks dynamically assign themselves an address when first attached. The address is randomly selected from a range of allowable addresses. The address is then broadcast out over the network as a check to see if another device is already using the address. A device stores its selected address for use the next time it is turned on.

Node addresses are mapped to names that make the network easier to access by humans. When users want to access resources on the AppleTalk network, they do so by looking up the name of the resource using features of the Macintosh graphic interface. This makes it much easier to find exactly the printer you want to use or the user you wnat to send an electronic message to.

AppleTalk Phase 2 was introduced in 1989 with the primary addition of extended addressing. Extended addressing increases the node identification numbers from 8 bits to 16 bits on EtherTalk and TokenTalk networks only. This overcame the previous restrictions of 254 nodes per network and allowed up to 16 million nodes. LocalTalk is still limited to 254 nodes.

Zones are an important AppleTalk concept. They are logical areas that primarily exist to make access to resources easier for users. A zone may extend across multiple networks. The whole network of zones is collectively called an internet. Routers can separate networks into segments that become zones. The router is then responsible for keeping track of network addresses and the cable systems associated with them.

Zones make it easier for users to find services. For example, rather than seeing a list of all users on the network, you can view a list of users in your own zone, which might be a department, a workgroup, or the floor you work on. Zones are assigned names, such as Accounting or Sales and appear in the Macintosh Chooser when a user goes to search for someone or do research. Choosing a zone reveals the names of devices attached in the zone.

NFS

See PS/2 - NFS Application Limitations

What is NFS?

Network File System (NFS) is file system that will mount remote file systems

across homogenous and heterogenous systems. NFS consists of a client and

server systems. An NFS server can export local directories for remote NFS

clients to use. NFS runs over IP using UDP (commonly). There are NFS

implementations that will work using TCP as the network transport service.

NFS was originally developed by Sun Microsystems Computer Corp. (SMCC) and

is now part of their Open Network Computing (ONC) initiative. NFS has been

accepted by the IETF in certain RFC's as a standard for file services on TCP/IP networks on the Internet.

TCP/IP

See Recommended IP Address

See TCP/IP Applications

What is TCP/IP?

Transmission Control Protocol/Internet Protocol (TCP/IP) is the main transport protocol used on the Internet for connectivity and transmission of data across heterogenous systems. It is an open standard which is available on most Unix systems, VMS and other minicomputer systems, many mainframe and super-computing systems and some microcomputer & PC systems.

TCP/IP is a software solution for network connectivity. There is little assumption on the hardware system used for actual physical connections. The most common hardware solution is Ethernet, but TCP/IP will also run on Token-Ring, AT&T StarLAN, microwave & spread spectrum systems , LocalTalk (needs a gateway), Serial lines (modems, serial connections) and other systems as well.

To run TCP/IP on a system you first need a hardware driver. On Macintosh systems, the hardware drivers are built into the system or is provided by the board manufacturer. On a PC system, there are different types of hardware drivers available both commercially and via public domain/shareware including the Packet driver specification by FTP Software, Inc., Microsoft's Network Device Interface Specification (NDIS), & Novell's Open Datalink Interface (ODI). Drivers for OS/2 systems are available from IBM and/or the board manufacturer (if they support OS/2). If a driver is not available for your hardware, look for a shim. This is a software device which translates between two driver specifications. There are shims for ODI-on-NDIS, NDIS-on-Packet driver. ODI-on-Packet driver, etc. usually publically available.

You then need a TCP/IP stack. This is package specific usually comes with every product. Each such stack has its own requirements for hardware drivers. you must find a combination of driver & TCP/IP stack which is compatible with your hardware & system. Macintosh's do not have a problem since most Macintosh systems use the MacTCP stack which is available from Apple and is provided with most if not all Macintosh TCP/IP packages. PC systems have something close to a standard in TCP applications called the Windows Sockets API (Winsock). [Note: This is not specific only to TCP/IP it is a general standard for networking on PC irrelevant of the transport protocol. Hence, there may be versions for NetBEUI, IPX, etc.]. The Winsock API is avaialble in 16 bit and 32 bit versions. The 32 bit versions are for Windows NT systems. Winsock is implemented in Dynamically Loaded Libraries or DLLs. Currently work is under way to develop a freeware Winsock DLL but many commercial versions are available.

With the TCP/IP stack in hand, you then need all the TCP/IP application programs such as Telnet, FTP, mail, etc. Just about every TCP/IP package has a corresponding set of applications although some do not provide all the different applications available.