Digital wireless SNAP2410 series Manuale utente

SNAP2410/2414/2420

Spread Spectrum

Network Access Points

Installation Guide

April 20, 2000

One Meca Way

Norcross, Georgia 30093

www.digital-wireless.com

(770) 564-5540

Transmitter Module FCCID: HSW-2410M.

Note: This unit has been tested and found to comply

with the limits for a class A 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 and, if not

installed and used in accordance with the instruction

manual, may cause harmful interference to radio

communications. Operation of this equipment in a

residential area is likely to cause harmful interference

in which case the user will be required to correct the

interference at his own expense. Commensurate with

EIRP limits specified in FCC Rules 15.247b, this

device may not be used with antennas that exceed

36dB of gain in point-to-point applications or 16dB of

gain in multi-point applications.

Table of Contents

Introduction...................................................................................................... 1

Getting Started................................................................................................. 2

Connecting the SNAP.................................................................................... 2

SNAP Status Indicators ................................................................................. 3

Configuring the SNAP.................................................................................... 3

SNAP Operation............................................................................................... 5

Overview....................................................................................................... 5

TCP/IP Addresses......................................................................................... 5

Seamless Roaming........................................................................................ 6

Synchronization............................................................................................. 7

AP Mode Operation....................................................................................... 7

PPP Operation .............................................................................................. 8

4-Port Hub..................................................................................................... 8

SNAP Command Set........................................................................................ 9

SNAP System Commands............................................................................. 9

Ethernet Commands.....................................................................................10

SNAP Radio Commands...............................................................................11

AP Mode Commands....................................................................................12

PPP Mode Commands .................................................................................13

Radio Modem Configuration ............................................................................15

Radio Commands.........................................................................................15

SNAP Datagram Protocol (SDP)......................................................................17

Overview......................................................................................................17

SDP Header.................................................................................................17

SDP Messages.............................................................................................18

Troubleshooting ..............................................................................................21

Technical Support.........................................................................................21

Quick Reference..............................................................................................22

Specifications..................................................................................................25

Warranty.........................................................................................................26

2000 Digital Wireless Corporation 1042000

INTRODUCTION

The SNAP2410 family of products from Digital Wireless Corporation provides Ethernet

connectivity to networks of WIT2410 radios. Built around the WIT2410, SNAP products

provide a 10BaseT connection to Ethernet networks and function as base stations for

remote devices containing WIT2410 transceivers. By supporting seamless roaming,

multiple SNAPs can be connected to a network to provide practically unlimited coverage

area. To simplify system installation some SNAPs have built-in 4-port hubs with an

uplink port. In addition, these SNAPs allow for power to be distributed through the hub

ports.

Depending on the model, SNAPs have one or two WIT2410 transceivers. Each radio can

support 62 simultaneous remotes. Thus SNAPs can support up to 124 simultaneous

remotes. Each remote radio has a unique ID number, so the number of remotes that can

communicate with a SNAP is unlimited, subject to a limit of 62 remotes at any one time.

The communication between the SNAP and the WIT2410 remotes is performed using the

WIT2410 over-the-air protocol. Thus the SNAP products are 802.3 compatible but not

802.11 compatible. By using the 460Kbps over-the-air data rate the WIT2410 protocol,

the full range of WIT2410 radios is realized, three times the range of most 802.11

products.

The SNAPs enjoy the same benefits of frequency-hopping spread spectrum technology

that the WIT2410s do. Namely, the immunity to multipath fading and resistance to

jamming that is provided by changing frequency every few milliseconds. Operating in the

2.4GHz ISM band, SNAPs can be used license-free worldwide and are not subject to the

congestion in the 900MHz band caused by cordless telephones.

The SNAP has two modes of operation, AP and PPP. The default mode is the AP mode.

In this mode the SNAP uses a special protocol mode called SDP(SNAP Datagram

Protocol). In order to send receive or transmit data from the SNAP, the application

software must use this protocol. The user may use the API roam library included with

the SNAP to help shorten software development.

The SNAP can also be configured as a PPP server. This allows any computer with a

remote to connect to the same network as the SNAP. These computers then could access

any files on the network and support browser-based applications.

2000 Digital Wireless Corporation 2042000

GETTING STARTED

The SNAP family of wireless Ethernet modems are easy to install and operate. In most

instances, the only installation steps will be setting IP addresses, selecting one modem as

the master and connecting the antenna, power and Ethernet cable.

Connecting the SNAP

Figure 1 identifies the various connectors on the rear of the SNAP2410.

Figure 1. SNAP Rear Panel Diagram

The antenna connector is a TNC type connector. An antenna may be connected directly

to this connector. Alternatively, an antenna may be located away from the SNAP using

RF cable to connect the SNAP to the antenna. Digital Wireless does not recommend

using RF cables longer than 5 feet. If more distance is required between the SNAP and

the antenna, high-quality, low-loss RF feed line must be used.

The 10BaseT Ethernet connector is the standard RJ-45 connector. The connector is wired

to be able to connect directly to an Ethernet hub using a straight-through cable. If it is

desired to connect the SNAP directly to a PC without a hub, the SNAP must be

connected with a cross-over cable.

The synchronizing signals are provided for special applications where multiple master

SNAPs are employed in an environment with slave SNAPs that are moving. The

synchronizing signals are RS-485 levels and may be connected using an RJ-11 connector.

In most instances the synchronizing signals are not required and may be left unconnected.

The power connector is a 2-pin DIN type connector. The provided AC adapter provides a

9 volt power level to the SNAP. The SNAP can accept DC voltages ranging between

7VDC and 26VDC if alternative power supplies are to be used.

Power Connector Synchronizing Signals 10BaseT Ethernet Connector

TNC Antenna Connector

2000 Digital Wireless Corporation 3042000

Figure 2. SNAP2410 Front Panel Diagram

The Configuration Port is an RS-232 serial port that may be used to configure the SNAP.

This is useful when the default IP address of the SNAP cannot be used with the existing

network preventing configuration through a telnet session. See the section Configuring

the SNAP for details of using this port.

SNAP Status Indicators

The PWR indicator on the front panel indicates that power is applied to the SNAP and

that the power switch is in the ON position.

TXD and RXD are indicators of data activity. They indicate the transmission and

reception of data over the Ethernet connection. Note that these LEDs can be active even

when the SNAP has no remote radios registered.

The COLL indicator is illuminated whenever packets collide on the network segment to

which the SEM is connected. As such, this is rough indicator of the level of traffic on the

network segment. If this LED is glowing brightly on a continuous basis, the throughput

of the SEM may appear to be reduced.

The LINK indicator when illuminated indicates a good connection to the Ethernet

network. If this LED is not on, it can indicate a cross-wired connection between the

SNAP and the network. It may also indicate a faulty cable connection.

Configuring the SNAP

SNAPs are shipped from the factory with default settings that include a default IP address

of 192.168.0.254. The network that the SNAP is connecting to must be compatible with

10BaseT products. The SNAP will not work if the network only supports 100BaseT

products. Before connecting a default configured SNAP to an active network, ask the

network system administrator to make sure that the default IP number will not cause any

SNAP 2410

2.4 GHz SPREAD SPECTRUM WIRELESS ETHERNET MODEM

Power Switch Status Indicators Configuration Port

2000 Digital Wireless Corporation 4042000

problems on the network and that the SNAP will be recognized by the network. If the

default IP address conflicts with a device on the existing network, the SNAP will need to

be configured through the serial port.

The SNAP can be configured two ways. The first is through the serial port. The settings

for the serial port are 38400 baud, 8 data bits, 1 stop bit, and no parity. WinSNAP will

automatically find the appropriate serial port and configure the serial port settings for

you. The software will inform you of its progress and any problems that arise. After a

few seconds the SNAP firmware version is displayed followed by the SNAP> prompt.

The second configuration method is through a telnet session. Most telnet programs work

with the SNAP. Windows 95/98/NT/2000 have a telnet program that works with the

SNAP. If there are no conflicts with the default IP number, initiate a telnet session to the

SNAP. A telnet session can be started by clicking on Start->Run if you have Windows

95/98/NT/2000 and the TCP/IP client has been installed. Enter the following information

in the dialog box:

telnet 192.168.0.254

A telnet window will open up. The first line is the version of the SNAP firmware

followed by the prompt:

SNAP>

To change the IP number of the SNAP, use the ip command.

ip <xxx.xxx.xxx.xxx> {yyy.yyy.yyy.yyy}

Where x is the new IP address, and y is the optional netmask number.

Store the changed configuration parameters in non-volatile memory with the save

command:

save<CR>

The SNAP will report back the time it took to the save the information. Reset the SNAP

by typing:

reset<CR>

The SNAP can also be reset by cycling power. Whenever a reset is executed on the

SNAP, the telnet session will be lost. It will take the SNAP about 30 seconds to

reinitialize after a reset or after cycling power.

Note: The save and reset commands must be entered after modifying the

default configuration. Failure to do so will result in the factory defaults to

be used.

2000 Digital Wireless Corporation 5042000

SNAP OPERATION

Overview

At the most basic level, SNAPs can be thought of as Ethernet-to-serial interface adapters.

That is, they take data from a host application over a 10BaseT Ethernet connection,

remove the Ethernet header information, format the data for WIT2410 radios and

transmit the data to the on-board WIT2410 through a high-speed serial interface. In the

other data flow direction, the on-board WIT2410 receives data from a remote WIT2410

device. The SNAP takes this data and provides the necessary Ethernet datagram

encapsulation and transmits the datagram to the host application over the connected

network.

A SNAP can be used standalone, or a group of SNAPs can be connected together through

a 10BaseT hub to provide seamless roaming over a larger area. When seamless roaming

operation is desired, the SNAPs must be synchronized with each other. This

synchronization is accomplished either over the Ethernet network or through a

differential Sync signal when time delay devices (such as routers) are between SNAPs.

See the section on Synchronization for details.

Communication between the host application SNAPs can occur at one of two levels.

Provided with the SNAP is a library of C routines that constitute a high level API for

workstation-based applications. Alternatively, host applications can communicate with a

SNAP using the SNAP Datagram Protocol (SDP). This protocol is described in detail

later in this manual.

The SNAP has a serial Configuration port in addition to the 10BaseT port. This port

allows configuration of the SNAP without having to connect it to a network. The

WinSNAP configuration utility provided with the SNAP is used to configure the SNAP

through the serial Configuration port. Any configuration of the SNAP can be performed

using either the Configuration port or over the network.

TCP/IP Addresses

Each SNAP must be configured with a unique IP address that is appropriate for the

network where the SNAP will be used. The IP address can be set using the ip command

through the serial-port interface. The ip command takes one or two parameters. The first

parameter specifies the IP address for the SNAP, and the second optional parameter, if

present, specifies the netmask for the SNAP. If the second parameter is not used, the

netmask is set to the default netmask for the IP address specified. For example, the

command:

ip 192.168.0.1

will set the SNAP’s IP address to 192.168.0.1 and the netmask will remain

255.255.255.0.

2000 Digital Wireless Corporation 6042000

The command:

ip 192.168.1.233 255.255.255.192

will set the SNAP’s IP address to 192.168.1.233 and will change the netmask to

255.255.255.192. The ip command without any parameters will display the current

setting of the IP address and netmask. The SNAP includes a simple ping command that

can be used to test the IP address and routing table settings.

The SNAP can also obtain its IP address from a BOOTP server if one is present in the

network. The BOOTP server will require the Ethernet hardware MAC address to be able

to assign the IP address to the SNAP. The Ethernet hardwate MAC address of the SNAP

is configured as 00:30:66:XX:YY:ZZ, where XX:YY:ZZ is the unique ID of the SNAP’s

“radio A”.

The route command can be used to modify and display the IP routing table entries. To

display the routing table, use the route list command. There will always be one entry in

the routing table that corresponds to the IP address of the SNAP. For most applications,

if any routing table entries are required, it will be sufficient to set a default route. To set

the default route, use the command:

route add default <gwaddr>

where <gwaddr> is the IP address of the default gateway (usually a router or routing

host). To remove the default route, use the command “route del default”. To add a route

to a particular network or host, use the command “route add <dest> <gw> [<netmask>]”,

where “<dest>” is the destination network or host IP address, “<gw>” is the IP address of

the gateway, and the optional “<netmask>” is the netmask which defines the destination

network.

Seamless Roaming

The SNAP2410 allows remote radios to seamlessly roam between multiple SNAP2410.

The remote radios can also be configured not to roam if this is the required operating

condition. In order for the remote to be able to roam seamless the <wg> parameter must

be set to 2. When the RSSI (receive signal strength indictor) of the remote reaches a

certain threshold, the remote will start looking for another SNAP with a higher RSSI.

The SNAP will be notified with a CONNECT and DISCONNECT packet when a remote

leaves or connects with a SNAP.

To facilitate seamless roaming among a group of SNAPs, the SNAPs use Ethernet

packets to synchronize time relative to each other. A single “master” SNAP will

broadcast (or multicast) special UDP datagrams to the “slave” SNAPs to deliver timing

information through the network. The SNAPs can also synchronize with one another by

RJ-11 cable (telephone cable). The RJ-11 method of synchronization uses a daisy chain

fashion to connect the SNAPs together. The SNAPs need to be synchronized this way if

2000 Digital Wireless Corporation 7042000

the ethernet packets can not be transmitted in a timely manner, such as going through a

router.

Synchronization

The SNAP uses broadcast or multicast datagrams for time synchronization. The default

is for the master SNAP to broadcast datagrams to the 255.255.255.255 all-hosts IP

broadcast address. Using the “sys xcast <ipaddr>”, SNAPs can be configured to use a

more limited IP broadcast address, or a multicast address. All SNAPs in a network

should be configured with the same “xcast” address. The use of multicast addresses is

preferred so that synchronization datagrams do not interfere with hosts other than the

SNAPs. Note that the SNAPs use UDP port 2410 as the source and destination UDP port

numbers in the synchronization packets.

The command “sync master” is used to set a SNAP to the master for time

synchronization, and the command “sync slave” is used to set a SNAP to be a slave for

time synchronization. There should be one master in a given network, even if there is

only one SNAP in the network.

There may be a time when there will be SNAP on different sides of a network router.

This situation could cause the SNAPs not to be synchronized. This is where the RJ-11

sync connectors can be used. If the remotes will need to be able to roam between the

SNAP located on different sides of the network router, the SNAP will have to be

connected together using the RJ-11 connectors. The cable will only need to be two

twisted pair. This is the same as regular phone cable. If there are more than two SNAPs

in the network, the SNAPs will need to be daisy chained together.

AP Mode Operation

The default operating mode of the SNAP is AP mode. This mode is optimized for

communications between a workstation or workstations on an Ethernet network and a

network of WIT2410-based devices. The AP mode assumes that there is limited

intelligence in the remote host. The AP mode is designed to allow the remote host

devices to send and receive data to the remote WIT2410 in transparent mode.

Data exchanges between the SNAP and workstations on the network are made using the

SDP protocol. This protocol is described in detail later on in this manual. To shorten

software development time, a C library is included that will help with the SNAP protocol.

roamlib will help in the developing the software needed to talk to the remote radios from

the SNAP. Also included is a simple multi-window (one per remote) ethernet chat

program, roam.exe. This program allows the user to send data to the SNAP and to the

remote. This program is based on the roamlib. In order for roam.exe to work the “sys

xcast” must be 224.5.5.5, the “sdp” must be 224.1.2.3 and the source and destination port

numbers must be 2411 and 2412 respectively. These are the default settings. Using the

roam library requires the use of winsock.dll. This file should already be included on any

Windows 95/98/NT PC that has TCP/IP installed as a protocol.

Questo manuale è adatto per i seguenti modelli

Indice

Manuali Punto di accesso wireless popolari di altre marche

D-Link

D-Link DWL-2100AP - AirPlus Xtreme G Manuale utente

Ubiquiti

Ubiquiti NanoStation NSM2 Manuale utente

Cisco

Cisco Aironet 1550 Series Manuale utente

Aruba

Aruba IAP-335 Manuale utente

Advantek Networks

Advantek Networks AWN-AP-54MR Manuale utente

IP-COM

IP-COM AP355 Manuale utente

Buffalo

Buffalo AirStation WLA-L11G Manuale utente

EnGenius

EnGenius EnStationACv2 Manuale utente

D-Link

D-Link DAP-3662 Manuale utente

xG Technology

xG Technology xMax CN1300 Manuale utente

Widelink

Widelink ezWave WAP-1100 Series Manuale utente

Edimax

Edimax CAP1200 Manuale utente

Ubiquiti

Ubiquiti LBE-5AC-Gen2 Manuale utente

Aruba

Aruba AP-203R Manuale utente

LuXout Shades

LuXout Shades LUXSHADE MOTION Manuale utente

CreatComm

CreatComm TB5F Manuale utente

SineDigital

SineDigital MW-1500AP(H) Manuale utente

TP-Link

TP-Link AP9650 V1 Manuale utente