Bay Networks 3395A User manual

*893-826-A*
January 1995
Bay Networks, Inc. Corporate Headquarters
4401 Great America Parkway
Santa Clara, CA 95054 8 Federal Street Billerica, MA 01821
Configuring the
Model 3395A Access
Serving Features

ii 893-826-A
© 1994 by Bay Networks, Inc. All rights reserved.
Trademarks
SynOptics and SynOptics Communications are registered trademarks of Bay Networks, Inc. Bay
Networks, Bay Networks Press, and Lattis System 3000 are trademarks of Bay Networks, Inc.
Other brand and product names are registered trademarks or trademarks of their respective holders.
Statement of Conditions
In the interest of improving internal design, operational function, and/or reliability, Bay Networks,
Inc. reserves the right to make changes to the products described in this document without notice.
Bay Networks, Inc. does not assume any liability that may occur due to the use or application of the
product(s) or circuit layout(s) described herein.
Federal Communications Commission (FCC) Statement
Note: This equipment has been tested and found to comply with the limits for a ClassA digital
device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio frequency energy. If it is not
installed and used in accordance with the instruction manual, it may cause harmful interference to
radio communications. Operation of this equipment in a residential area is likely to cause harmful
interference, in which case users will be required to take whatever measures may be necessary to
correct the interference at their own expense.
Electromagnetic Emissions
Meets requirements of:
FCC Part 15, SubpartsA and B, Class A
EN 55 022 (CISPR 22:1985), Class A
General License VDE 0871, Class B (AmtsblVfg No. 243/1991 and Vfg 46/1992)
VCCI Class 1 ITE

893-826-A iii
Contents
Preface
Overview xi
Conventions xi
Ordering SynOptics Publications xii
Bay Networks-SynOptics Customer Support xii
InfoFACTS xiii
CompuServe xiii
PhonePlus xiii
Chapter 1 Introducing the Communication Server
What is a Communication Server? 1-1
Point-to-Point Protocol 1-3
IP/PPP (IPCP) Features 1-3
IPX/PPP (IPXCP) Features 1-6
Serial Line Internet Protocol (SLIP) 1-9
Xremote 1-11
ARAP Features 1-13
Automatic Protocol Detection 1-16
IP and IPX Routing 1-17
Dynamic Routing 1-17
Static Routing 1-18
IP and IPX Packet Filtering 1-18
Command Control Language (CCL) Scripts 1-19
Chapter 2 Basic Setup Activities for Access Serving
An Overview to Setting Up the Communication Server 2-1
Preliminary Tasks 2-1
Specific Activities for Configuring Access Serving Features 2-2
Information about Model 3395A Server Cabling Methods 2-3
Six-Wire Cabling 2-4
Eight-Wire Cabling 2-5
Selecting Protocols and Features 2-7
Configuring Ports to Detect Multiple Protocols (APD) 2-9
Chapter 3 Setting Up Basic Modem Applications
Basic Modem Port Setup 3-1
Modem Control Issues 3-1
Speed or Autobaud 3-2
Flow Control 3-3
Setting Up Dial-in Ports 3-4
Setting Up Dial-out Ports 3-5
Configuring a LAT Application Port at a VMS Host 3-6
Setting Up Dial-back Ports 3-7
Using Dial-back Scripts on the Communication Server 3-8
Configuring PORT Characteristics 3-8
Setting Up a Dial-back Script Server 3-9
Script File Structure and Guidelines 3-10
Directory Requirements 3-11
Script File Execution and Processing 3-12

iv 893-826-A
Chapter 4 Point-to-Point Protocol (PPP)
Enabling Protocols on the Server 4-1
Configuring a PPP Port for Modem Support 4-2
Configuring PPP 4-2
Enabling PPP at Specific Ports 4-2
Specifying Optional PPP Port Characteristics 4-3
Configuring IPCP Connections 4-4
Assigning Local and Remote IP Addresses to PPP Ports 4-5
Specifying Optional IPCP Port Characteristics 4-5
Specifying IP Static Routes 4-6
Examples of IPCP Single-Node Configuration 4-6
A PC with an Internet Address Within the LAN Subnet 4-7
A PC with an Internet Address Outside of the LAN Subnet 4-8
A PC with No Configured Internet Address 4-9
Example of an IPCP Network Configuration 4-10
Configuring IPXCP Connections 4-12
Specify IPXCP-Related SERVER characteristics 4-12
Defining IPX Protocol Packet Types 4-13
Defining IPX Network Numbers 4-13
SERVER IPX RIP Characteristics 4-14
SERVER IPX SAP Characteristics 4-15
Specify PORT Characteristics 4-15
Basic PORT IPX Characteristics 4-15
PORT IPX RIP Characteristics 4-16
PORT IPX SAP Characteristics 4-17
Specify Static Routes and Services 4-18
Chapter 5 Serial Line Internet Protocol (SLIP)
Configuring Ports to Use SLIP and CSLIP 5-1
Configuring Modem Support for SLIP Links 5-1
Enabling SLIP/CSLIP at Specific Ports 5-1
Assigning SLIP Addresses to Ports 5-3
SLIP Sessions 5-4
Example Configurations 5-4
Single-Node Applications 5-4
Direct Connection of a Host to a Serial Port 5-4
Dial-in SLIP Connection 5-5
Network Applications 5-6
Chapter 6 Setting Up ARAP
ARAP Setup 6-1
Enable the Server ARAP Protocol 6-1
Specify SERVER Characteristics 6-2
Specify PORT Characteristics 6-3
Configuring an ARAP Port for Modem Support 6-3
Enabling ARAP at Specific Ports 6-3
Specifying Optional ARAP Port Characteristics 6-4
Install CCL Scripts 6-4
Using ARAP with Authentication and Dial-back Features 6-5
Modifying Dial-back Scripts for ARAP Ports 6-11

893-826-A v
ARAP Planning Considerations 6-12
Example 6-13
Diagnostic Cabling 6-13
Chapter 7 Model 3395A Server Support for the Xremote Protocol
Starting Up the XDM Host 7-1
Configuring the Communication Server for Xremote Support 7-2
Enabling the Xremote Protocol on the Server 7-2
Defining Remote Font Servers 7-3
tftp Security on Font Servers 7-4
Defining Xremote Characteristics at Server Ports 7-5
Examples 7-5
Establishing an Xremote Session 7-6
Logging Out of the X Session 7-8
Using a Script to Configure the Server for Xremote Support 7-8
Enhancing Security for Xremote Users 7-10
The Communication Server Password 7-10
The SecurID Authentication System 7-10
The Kerberos Security System 7-10
Login Scripts and Dial-back Scripts 7-11
Notes on Memory Requirements for Xremote 7-11
How Xremote Can Affect Server Performance 7-11
Memory Requirements for Sessions and Windows 7-12
Notes and Restrictions 7-13
Chapter 8 Using CCL Scripts
Types of CCL Scripts Available 8-2
Communication Server Setup 8-3
Specify SERVER Characteristics 8-3
Specify PORT Characteristics 8-3
Script Server Setup 8-4
Directory Requirements 8-4
Installing CCL Scripts at Script Servers 8-5
Installing CCL Scripts at Macintosh Computers 8-6
Modifying CCL Scripts 8-7
Basic Format of a CCL Script 8-7
Modifying a CCL Script for Macintosh Computers 8-9
Modifying a CCL Script to Use Error Correction or Compression 8-11
Example Model 3395A Server CCL Extensions 8-12
Example of a Typical CCL Script 8-14
Appendix A Modem and Flow Control Operation
Modem Control Signal Interaction A-1
Dial-in Modems that Support RNG A-1
Dial-in Modems that Do Not Support RNG A-2
Dial-in to Remote Access Ports that Do Not Support RNG A-4
Dial-out Modems A-4
Dial-in/Dial-out Modems that Support RNG A-5
Dial-in/Dial-out Modems that Do Not Support RNG A-7

vi 893-826-A
Flow Control A-9
Software Flow Control A-9
Hardware Flow Control A-10
Setup A-10
Flow Control Operation A-11
Hardware Flow Control Operation Using the Modem Control Signal
Lines A-12
Index

893-826-A vii
Figures
Figure 1-1. Network configuration with communication servers 1-2
Figure 1-2. IPCP single-node configuration 1-4
Figure 1-3. An IPCP network configuration 1-5
Figure 1-4. Basic IPXCP configuration using communication servers 1-6
Figure 1-5. IPXCP “LAN-to-LAN” configuration using communication
servers 1-7
Figure 1-6. SLIP connections to remote network, remote PC 1-10
Figure 1-7. Conventional Xremote implementation 1-12
Figure 1-8. An Xterminal connected to a Model 3395A server 1-13
Figure 1-9. Standard AppleTalk remote access configuration 1-14
Figure 1-10. AppleTalk remote access configuration using communication
servers 1-15
Figure 2-1. Modular cables for connecting a modem (6-wire port) 2-4
Figure 2-2. Modular cables for RTS/CTS flow control (6-wire port) 2-5
Figure 2-3. Modular cables for connecting a modem (8-wire port) 2-6
Figure 2-4. Modular cables for RTS/CTS flow control (8-wire port) 2-7
Figure 3-1. Example script server directory structure 3-10
Figure 4-1. A PC with an Internet address within the LAN subnet 4-7
Figure 4-2. A PC with an Internet address outside of the LAN subnet 4-8
Figure 4-3. A PC with no configured Internet address 4-10
Figure 4-4. Two communication servers in a back-to-back gateway 4-11
Figure 5-1. Direct SLIP connection 5-5
Figure 5-2. Dial-in SLIP connection 5-6
Figure 5-3. SLIP connections to remote network 5-7
Figure 6-1. Operation of authentication and security methods (part 1) 6-7
Figure 6-2. Operation of authentication and security methods (part 2) 6-8
Figure 6-3. Operation of authentication and security methods (part 3) 6-9
Figure 6-4. Operation of authentication and security methods (part 4) 6-10
Figure 6-5. Modular cables for connecting a Macintosh computer 6-13
Figure 7-1. Font servers 7-3
Figure A-1. State diagram for dial-in modems that support RNG A-2
Figure A-2. State diagram for dial-in modems that do not support RNG A-3
Figure A-3. State diagram for dial-out modems A-5
Figure A-4. State diagram for dial-in/dial-out modems that support
RNG A-7
Figure A-5. State diagram for dial-in/dial-out modems that do not support
RNG A-9

viii 893-826-A

ix 893-826-A
Tables
Table 2-1. Cabling support for modem applications 2-3
Table 2-2. Modem control/flow control feature support 2-3
Table 2-3. Memory usage for features and protocols 2-8
Table 7-1. Default files 7-1
Table 7-2. Settings for port characteristics 7-7

x 893-826-A

893-826-A xi
Preface
This manual describes the configuration, setup, and management of a
communication server software package, supplied by Bay Networks, Inc. to
provide access to network services from remote locations. A communication
server is composed of a Model 3395A Terminal Server working in conjunction
with the Multiprotocol Communication Server software.
This manual is intended for network and communication server managers.
Overview
This manual is organized as follows:
Chapter 1 Introduces Multiprotocol Communication Server software and
describes the access serving features available on
communication servers.
Chapter 2 Provides an overview of the server configuration process for
supporting access serving features, a discussion of the cabling
requirements, directions for enabling the access serving
features, and related planning considerations.
Chapter 3 Describes how to configure basic modem applications such as
dial-in, dial-back, and dial-out modems.
Chapter 4 Describes how to set up the server to support connections
using the Point-to-Point Protocol (PPP).
Chapter 5 Describes how to set up the server to support connections
using the Serial Line Internet Protocol (SLIP).
Chapter 6 Describes how to set up the server to support connections
using the AppleTalk Remote Access Protocol (ARAP).
Chapter 7 Describes how to set up the server to support connections
using the Xremote Protocol.
Chapter 8 Describes how to configure ports to use CCL scripts.
Appendix A Describes how the modem control and flow control
functions operate. This information might be useful when
troubleshooting modem problems.
Conventions
This manual uses the following conventions:
• The CTRL key on the keyboard provides alternate functions when used
with some keyboard keys. “CTRL-A” indicates that you press both the
CTRL key and the letterA key at same time. The terminal server will echo
this control character as ^A.

Preface
xii 893-826-A
• Unless otherwise specified, commands are executed when you press the
RETURN key on the keyboard.
• The manual uses the following typographical conventions:
Monospace typeface
Indicates text displayed at a terminal (displays,
messages, system responses, etc).
Italics Indicates variables in commands and procedures.
• The following typeface indicates user input in response to system
prompts:
T53395> connect
• The server prompt for secure and nonprivileged users is this:
T53395>
The server prompt for privileged users is this:
T53395>>
This is the default communication server user interface prompt; the server
manager can specify a different prompt, so the prompt in use at your site
may be different.
• The following default user prompts will be shown (different prompt may
be in use at your site):
VMS
$
UNIX/ULTRIX
%
UNIX/ULTRIX Superuser #
DOS
C:\
Ordering SynOptics Publications
To purchase additional copies of this document or other publications for
SynOptics products, order by part number from Bay Networks Press™ at the
following numbers.You may also request a free catalog of Bay Networks Press
product publications.
• Phone: [phone]
• FAX: U.S/Canada: 1-800-582-8000, International: 1-916-939-1010
Bay Networks-SynOptics Customer Support
For assistance with installing and configuring your Bay Networks systems or with
post-installation questions or problems, contact your local reseller.
Bay Networks also offers a variety of additional support services to help you get
the most out of your network.

893-826-A xiii
Bay Networks-SynOptics Customer Support
InfoFACTS
InfoFACTS is a 24-hour automated service that sends free technical information
to your fax machine.You can locate documents that provide valuable reference
information for all Bay Networks-SynOptics products.
To use InfoFACTS, call 1-800-786-3228. (Outside the U.S. and Canada, call
408-764-1002.)
CompuServe
You can use your modem to easily gain access to Bay Networks technical
information through our support forums on CompuServe.You can interact with
other Bay Networks users and find libraries full of valuable support information
that you can download.
To access the Bay Networks forum, type GO BAYNETWORKS at any ! prompt.
For CompuServe membership information, call toll-free 1-800-524-3388 and ask
for representative number 591. In the United Kingdom, call Freephone
0800-289378. In Germany, call 0130-37-32. In the rest of Europe, call
44-272-760681. Outside the U.S., Canada, and Europe, call 614-529-1349 and
ask for representative number 591.
PhonePlus
Whether you need a fast response to a technical question or a more concentrated
and advanced level of technical support, PhonePlus™ PriorityAccess telephone
support programs can be tailored to your needs. With PhonePlus, you talk directly
with one of our highly qualified technical support engineers. Standard PhonePlus
is available from 6 a.m. to 5 p.m. Pacific Standard Time.
To purchase PhonePlus Priority Access telephone support, call 1-800-473-4911.
(Outside the U.S. and Canada, call 408-764-1000.)
For more information on PhonePlus and other Customer Service programs,
contact your local reseller or Bay Networks sales office.

Preface
Preface-xiv 893-826-A

893-826-A 1-1
Chapter 1 Introducing the Communication Server
A Model 3395A Terminal Server running the Multiprotocol Communication
Server software is called a communication server, part of the Lattis System
3000™ integrated family of Bay Networks™ products.
This chapter provides an overview to the following access serving features that
are available on a Multiprotocol Communication Server:
• Point-to-Point Protocol (PPP), including:
– Internet Packet Control Protocol (IPCP or “IP over PPP”)
– Internet Packet Exchange Control Protocol (IPXCP or “IPX over
PPP”)
• Serial Line Interface Protocol (SLIP) and Compressed Serial Line
Interface Protocol (CSLIP)
• Xremote Protocol
• AppleTalk Remote access (ARAP)
• Automatic Protocol Detection (APD)
• IP and IPX routing
• IP and IPX Packet Filtering
• CCL scripts
What is a Communication Server?
Communication servers support connections between serial-interface devices
and other devices connected to the Ethernet network. The serial-interface
devices include: terminals, serial printers, personal computers running terminal
emulation or networking software, modems, serial ports on other
communication servers, and host computer serial ports. Figure 1-1represents a
communication server configuration.
NOTE:
The access serving features discussed in this document require the use
of the multimegabyte image, TS3395M.SYS. This image requires greater than
the 1 MB of memory provided with the base models. Be sure that you have the
Model 3395A server with at least one set of expansion SIMMs to support the
multimegabyte image. Memory expansion for the Model 3395A server is
available by ordering the Model 773 SIMM Memory Option Kit. Memory for
the Model 3395 Terminal Server cannot be expanded.

Introducing the Communication Server
1-2 893-826-A
Figure 1-1. Network configuration with communication servers
Figure 1-1 shows that several different types of devices can be connected
to the serial ports of the communication server. Users at any of these devices
can gain access to any resources on the network, such as host computers,
workstations, etc, and resources available at other communication server ports.
Because the Multiprotocol Communication Server software supports multiple
communication protocols, these connections can be made regardless of the
operating system running at the desired resource.
Compare this configuration to operation without a communication server,
where users would need to go to a terminal that is directly connected to a serial
port on the host or node they want to use. With a communication server, users
can perform work on any computer that is connected to the network that the
communication server is on. Providing access from serial ports to host
computer resources is referred to as “terminal serving.”
Similarly, consider the example of a user who wants to print a job. Without a
communication server, the user would need to print the job to a printer that is
directly connected to a serial port on the host where the data is located. With a
communication server, many users can have access to a shared printer resource,
because the resource is located on the network. Providing shared printing
resources is also referred to as “printer serving.”
5446
VAX/VMS
system
Ethernet Local Area Network (LAN) Communications server
modules in chassis
UNIX
system
Printers
PCs Terminals
Modems
Data Switches
Host Systems
Novell NetWare
File Servers
Other devices
with serial
interfaces
Model 3000 Chassis
with Model 3395A
Server
Model 3000 Chassis
with Model 3395A
Server

Point-to-Point Protocol
893-826-A 1-3
For terminal serving and printer serving, the devices that provide services are
connected to a network and the users of those services usually work at a
location that is geographically local to the device offering the service. Serial
ports at communication servers can also be connected to modems, switches,
and other devices to provide access to services that are available at remote
locations or for users who are at remote locations. This type of connection is
referred to as “access serving.”
Access serving configurations include anything from simple dial-in and
dial-out modems for low-speed interactive traffic (such as terminal emulation,
text editing, file transfers, electronic mail) to more sophisticated applications.
Point-to-Point Protocol
The Point-to-Point Protocol (PPP) allows a personal computer (PC), another
communication server, or a router that also supports PPP to gain access to a
network, such as Internet networks (IP) or Novell NetWare networks (IPX),
through a serial port. PPP devices can connect to the communication server
directly over a serial line or through a modem.
PPP provides a standard method for transmitting multiprotocol datagrams over
point-to-point links. Because PPP is a datagram transmission service, it is not a
guaranteed delivery service. (To compensate, flow control methods and the
requirement by higher-level protocols that messages be acknowledged before
additional messages are sent means that most packets are delivered without
error.)
PPP provides an excellent foundation for other applications. PPP defines a Link
Control Protocol (LCP) for establishing, configuring, and testing the data-link
connections. PPP also provides a family of Network Control Protocols (NCP)
for establishing and configuring network layer protocols. The IP Control
Protocols (IPCP) and IPX Control Protocol (IPXCP) are NCPs supported by
the Model 3395A server PPP implementation.
IP/PPP (IPCP) Features
The Model 3395A server implementation of IPCP supports two general
network configurations: the single-node configuration and the network
configuration. In the single-node configuration, a PC running PPP is attached to
a communication server port over a serial line. In the network configuration,
two communication servers route IP traffic between two LANs with different
subnet addresses in the Internet.

Introducing the Communication Server
1-4 893-826-A
Figure 1-2 and Figure 1-3 show examples of the two network topologies.
Figure 1-2. IPCP single-node configuration
The PC in Figure 1-2 can have an address in the same Internet subnetwork, or
subnet, as the communication server or on a remote subnet with a different
Internet address. The PC can connect to the communication server port directly
or through a modem, as shown in this figure. When the PC and the
communication server are configured appropriately, the PC can gain access to
Internet devices on the LAN through the communication server port.
5109
Model 3000 Chassis
with Model 3395A
Server running PPP
PC
running PPP
Modem
Modem
Internet address:
140.179.78.20
Mask: 255.255.255.0
Serial
Line
Serial
Line
Internet address:
140.179.78.10
IP
Internet address:
140.179.78.50
Internet address
140.179.78.60
UNIX Host UNIX Host

Point-to-Point Protocol
893-826-A 1-5
Figure 1-3. An IPCP network configuration
The two LANs in Figure 1-3 represent different subnets on the Internet. Two
communication servers running IPCP, connected over a serial line, act as a
gateway or router between the two networks. Devices on LAN A can gain
access to devices on LAN B, and devices on LAN B can gain access to devices
on LAN A.
The following are other important features of the PPP IPCP implementation:
• Support for Van Jacobson compression
PPP links can transmit and receive packets that have been compressed
using the Van Jacobson compression algorithm (refer to RFC 1144).
Compression allows PPP links to operate with higher throughput (actual
performance depends on your application).
• Compatibility with Model 3395A server security mechanisms
IPCP can be used in conjunction with all Model 3395A server access
security methods.
• Model 3395A server product support
IPCP is supported on Model 3395A servers that use either the 6- or 8-wire
cabling methods and can run the following enhanced or multimegabyte
load image, TS3395M.SYS.
5108
Model 3000 Chassis
with Model 3395A
Server running PPP
Model 3000 Chassis
with Model 3395A
Server running PPP
IP
IP
IP over PPP
Network Address:
140.179.85.0
Serial Line
Network Address:
140.179.90.0
Network Address:
140.179.80.0 LAN A
LAN B

Introducing the Communication Server
1-6 893-826-A
IPX/PPP (IPXCP) Features
In Novell NetWare networks, communication is handled using a protocol
known as Internetwork Packet Exchange (IPX). IPX is a connectionless,
datagram protocol, which means that each packet contains all the information
necessary to deliver it to the final destination. The PPP specification defines
many Network Control Protocols (NCP) for establishing various network layer
protocols. IPX Control Protocol (IPXCP) is one such network control protocol
and specifies a means for handling IPX traffic running over a PPP link.
With Multiprotocol software, a communication server provides transparent
access to IPX services, devices, or networks. Specific applications include:
• Connecting a remote (dial-in) workstation or PC to the network.
This is a typical “remote office” or “user-to-LAN” application. Figure 1-4
depicts this IPXCP configuration.
Figure 1-4. Basic IPXCP configuration using communication servers
In this application, the users at the remote IPX clients have access to the Novell
services offered on the Novell Netware network (unless the network manager
chooses to limit that access). The user dials in when he or she needs access to
the services and disconnects when the services are no longer needed.
5433
Remote
IPX clients
Ethernet Local Area
Network (LAN)
Model 3000 Chassis
with Model 3395A
Server
PPP links
Modems
Modems
Novell NetWare
File Servers
Novell NetWare NetworkRemote Users
Printers