Chapter 3 - Administrator's Tasks
This chapter describes tasks that administrators typically perform when setting up Banyan networks. While no two Banyan networks are the same and individual network administrators may set up their networks in slightly different ways, all Banyan network administrator's tasks include:
Planning the network topology Installing Banyan networking software and software options Setting up and configuring hardware
Banyan networks vary in size and complexity. Planning network topologies depends primarily on the needs of the network users and the networking hardware. In addition, there are corollary issues affecting network security.
Efficient network planning depends on a careful analysis of the physical location of users and hardware in proposed network. Because it is not always easy to project the final size of your network, it is important to plan your network for easy expansion.
In most networks, servers are connected to workstations and other peripheral devices on a LAN. Individual servers in turn are connected to other servers by a LAN, a WAN, or both.
When planning network topologies:
In the early stages of your planning, concentrate on mapping and cabling the individual LAN or LANs in your network. Combine separate LANs if you are planning a multi-server network. Determine how much information networks will exchange across WANs. Plan WAN connections to mainframe computers, PDNs, and network LANs in distant locations accordingly. Determine the types of communications devices you need. Choose the appropriate Banyan serial communications software options.
For detailed information on planning network topologies, see Planning a Banyan Network.
The following section describes the hardware components you can install in Banyan networks to use Banyan LAN and WAN communication options.
The Banyan networking software runs on all popular LAN media. After you choose the particular LAN media, such as Ethernet, Token-Ring, or FDDI, obtain the following hardware:
LAN cards appropriate for the LAN type you chose (a card for each workstation) Sufficient cable to connect the servers and workstations together A set of the diskettes containing files required to run the workstation LAN cards under the Banyan networking software
Once you have assembled the hardware, consult Managing Workstations and your installation guide for information on installing the cards and the Banyan networking software required to run them.
Components and Options for WANs
To connect your network to a WAN, you need one of the following:
One of Banyan's ICA serial communications cards on the gateway server in your network. Chapter 5 describes the ICA cards currently available. For information on installing the ICA cards, see the Banyan ICA Installation Guide. A Promptus T1 card for full T1 communications. For information on installing and configuring this card, see the Banyan T1 Server-to-Server Guide.
Serial Communications Hardware
In a serial communications connection, information is transferred on serial communications lines between the communications ports on two computers. In a Banyan network, servers use an ICA serial communications card for serial communications. Each card:
Provides both synchronous and asynchronous communications Accepts standard serial communications connections using one of its six ports
The number of ICA cards you can install in a server depends on the server type. In high-end servers, you can install as many as five boards, each of which can have as many as six serial lines, for a total of 30 possible serial lines.
The equipment that connects the line from a communications port to a communications provider can be one of the following items:
Modem Modem eliminator/emulator Null-modem cable Channel Service Unit/Data Service Unit (CSU/DSU)
The choice of data communications equipment depends on option type, line speed, and line distance.
Serial Communications Lines
Serial communications lines supported by ICA cards can run at line speeds of 110 bps to 384 Kbps. Available line speeds depend on the software option, communications card, port, and modem you use. The two types of communications lines are switched lines and dedicated lines.
Switched lines connect endpoints over lines in public telephone systems. The term switched line can also refer to any medium that connects two endpoints using a non-dedicated circuit passing through a switching system. Other terms commonly used to describe a switched line are public switched telephone network and dial-up network.
On switched lines, two computers establish a connection using a call set-up procedure as follows:
1. One computer initiates the call.
2. The other computer answers.
3. The phone system establishes a temporary switched circuit like a person-to-person phone call between the two endpoints in the connection.
4. The temporary circuit is maintained until either end of the connection "hangs up." Then the circuit becomes available for another connection.
Switched lines require modems to place and to receive calls over the telephone system. A standard telephone line uses a two-wire, voice-grade line. A modular telephone cord with a connector on both ends connects the computer to the phone system. One end plugs into a telephone wall jack, and the other end plugs into the modem attached to the computer.
Dedicated lines use fixed communications circuits to connect two end points. A fixed circuit is a direct, dedicated link between two computers. No call set-up procedure is necessary because the circuit is fixed. The circuit is available to those computers only, and the connection remains unbroken unless there is a problem with the line.
The two types of dedicated lines are leased lines, used for long distances, and short-haul lines, used for short distances.
A leased line is a type of dedicated line (either voice-grade or Fractional T1), privately owned or leased from the telephone company or long-distance carrier. Often, the line is conditioned to provide lower error rates and better data transmission quality for high-speed communications than is available from regular phone lines. Leased lines require the use of modems, but the modems do not need a dialing feature.
A short-haul line is a type of dedicated line used when the distance between the two computers is quite short (usually not more than 50 feet). Short-haul lines often use a modem eliminator or a null-modem cable in place of two modems.
For asynchronous short-haul communications, you can use either a modem eliminator or a null-modem cable. Banyan recommends a maximum line length of 50 feet for a null-modem cable or for the cable that connects the port and the modem eliminator. The modem eliminator must support this distance.
A dedicated line can be a two-wire or four-wire circuit. Be aware that on a two-wire circuit, some modems operate only in half-duplex mode.
The terminology for dedicated lines is not strictly defined. From a software perspective, leased lines and short-haul lines are equivalent. The following terms are often used to apply to both: dedicated lines, direct-connect lines, and private lines.
Modems support one of two types of connections:
Synchronous Connections - Synchronous connections use clocking signals to keep data transfers synchronized.
Asynchronous Connections - Asynchronous connections use start bits to keep data transfer synchronized.
Many modern modems support either type. Earlier modems supported one or the other.
The Banyan networking software provides support for modems through a modem script. The Modem Scripting Guide describes the modem scripting language and shows you how to add support for new modems or create your own customized modem scripts.
The Banyan networking software comes with default listening scripts and calling scripts for both asynchronous lines and synchronous connections. These scripts are:
asy_lstn.sct, asy_call.sct - Default listening and calling scripts for asynchronous connections.
synclstn.sct, synccall.sct - Default listening and calling scripts for synchronous connections.
The Modem Scripting Guide describes these scripts in detail.
The Script Interpreter
The script interpreter is a program that interprets the script files. It understands and carries out the actions specified in the script file. For example, when a typical script runs, the script interpreter does the following:
Takes control of the ICA slot and line that was configured for communication Reads the entire script file into memory Executes script commands (for example, send ATDT) and sends the commands through the correct ICA slot and line At the end of the script processing, returns control of the line to the appropriate protocol driver and leaves a status (succeeded or failed) in shared memory
When the Scripts Run
When you assign a line at the server, the script interpreter automatically runs the listening script.
When a connection is initiated, either manually or through scheduling, the listening script is terminated and the calling script is run. When the connection ends, the listening script is re-run. Figure 3-1 illustrates this.
When a line is assigned, the listening script runs.
When a connection is made, the calling script runs. When the connection ends, the listening script re-runs.
No special scripts run when a line disconnects. If a modem requires particular disconnect commands, place these at the beginning of the listening script. That way they will run first when the listening script is restarted after a line disconnects.
Full T1 and Fractional T1 Support
T1 is a fiber-based, digital communications carrier. Full T1 communication provides long-distance, high speed, reliable transmission of data between servers. The Banyan T1 Server-to-Server option, which is currently supported on the Promptus T1 card provides full T1 support.
Full T1 service provides use of the whole T1 line; that is, all 24 channels, and the maximum data rate (1.536 Mbps). For Full T1 service, each server must have a T1 card installed. A single server can have up to five cards, thereby allowing that server to communicate with up to five other card-equipped servers. All T1 transmissions are point-to-point. The Banyan T1 Server-to-Server Guide describes how to configure the Banyan T1 Server-to-Server option on the Promptus T1 card.
Fractional T1 (FT1) is digital communication over T1 facilities that do not use all of the 24 digital circuits, called DS0s, on the T1 link. As the term implies, FT1 provides only a smaller portion of the line. You allocate each portion, or fraction, in 56 Kbps or 64 Kbps increments. This allocation means that the rate of transmission is correspondingly less. Chapter 6 describes how to configure an FT1 line. FT1 is currently supported on the ICA/HS, ICA/RM, and ICAplus cards.
Note: You cannot connect a server running T1 Server-to-Server on a Promptus T1 card to a server running FT1 on an ICAplus card.
Channel Service Unit/Data Service Units
A CSU/DSU acts as the interface between the long-distance carrier and one or more FT1 lines connected to an ICAplus card. The primary function of a CSU/DSU is to encode and manage digital information passed between the FT1 line and the ICA card. In addition, a CSU/DSU collects statistics on line traffic.
Full T1 communications usually require a CSU and a DSU. The Promptus T1 card comes with a built-in CSU/DSU; therefore, no separate CSU or DSU is required. Instead, a card-equipped server communicates directly with another card-equipped server.
After you install the hardware for your network, you must install the base Banyan networking software and configure the LAN cards. While the Banyan networking software automatically routes traffic between network servers and workstations running DOS and OS/2, you must still configure serial communications options such as X.25 and TCP/IP.
The Managing Communications Menu
Figure 3-2, shows the Managing Communications Menu. This menu lists choices for configuring communications software.
The following documents contain information about each menu selection:
To manage serial communications, see Chapter 7 in this guide. To set-up TCP/IP, see the Banyan TCP/IP Guide. To manage AppleTalk, see Managing AppleTalk on a VINES Network. To mange T1/E1 Server-to-Server, see Chapter 5 in this guide. To mange source level routing, see Chapter 4 in this guide. To manage VINES/IP, see Chapter 8 in this guide.
Some options, such as 3270/SNA and the Asynchronous Terminal Emulation option, require that you create services. StreetTalk Explorer lets you create services. For more information on creating services, see Managing VINES Services. For more information on specific options, see the guide for the option.
To configure a LAN or WAN card that is included as part of the VINES software, you must load the driver and configure the card. You do this using the Add Cards/Change Card Configuration menu. To configure a third party LAN or WAN card that is not included as part of the VINES software, you must install the new driver, using the Install/Remove Communications menu, and then configure the card using the Add Cards/Change Card Configuration menu. The following provides an overview of the steps. For complete details, see the VINES Server Installation Guide.
Note: Some systems require you to run hardware configuration software to install the network card. Typically, hardware configuration includes configuring the RAM, ROM, and Interrupt values for the network card.
You must run hardware configuration software before you use VINES to install and configure the network card. You must also use the same values when you install the network card on your VINES server as you did when you ran the hardware configuration software.
Use the Install/Remove Communications Drivers menu to install third party LAN cards onto a VINES server. These cards are supported, but do not appear under the Add Cards/Change Card Configuration menu until you configure them.
1. From the Operator Menu, choose the System Maintenance menu. The System Maintenance menu appears.
2. Choose Configure/Diagnose Server. The Banyan Server Configuration menu appears.
3. Choose Install/Remove Communications Drivers menu.
4. Place the driver diskette into the drive. Press ENTER.
The driver software is copied onto the server system.
To Load the Driver and Configure a LAN or WAN card
1. From the Operator Menu, choose the System Maintenance menu. The System Maintenance menu appears.
2. Choose Configure/Diagnose Server. The Banyan Server Configuration menu appears.
3. Choose Add Cards/Change Card Configuration. The Add/Change Card menu appears.
4. Choose ADD a Card. The Add a Card menu appears.
5. Use the arrow keys and choose the correct card type.
6. If you need to change the default settings, choose Change Card Settings. Use the arrow keys to choose the card you just added.
7. Enter the following information.
- Slot Number
- Card Number
- Card Interrupt
- I/O Address
- RAM Address
Follow the guidelines suggested by the manufacturer. If your system required you to run hardware configuration software to specify the RAM, ROM, or Interrupt value, be sure to enter the same values here as you entered during hardware configuration.
8. From the Add/Change Card menu, choose Save Configuration and Exit.
9. Reboot the server.