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Appendix C - Network Overview

including more sophisticated error handling, prioritization, and security features. It provides quality
service and accurate delivery by providing connection-oriented services between two end systems.
The transport layer controls the sequence of packets, regulates traffic flow, and recognizes duplicate
packets. It assigns packetized information which is a tracking number that is checked at the
destination. If data is missing from the packet, the transport layer at the receiving end arranges with
the transport layer of the sending system to have packets retransmitted. This layer ensures that all
data is received and in the proper order.

The session layer coordinates the exchange of information between systems by using conversational
techniques, or dialogues. Dialogues are not always required, but some applications may require a
way of knowing where to restart the transmission of data if a connection is temporarily lost, or may
require a periodic dialog to indicate the end of one data set and the start of a new one.

Presentation layer protocols are part of the operating system and the application the user runs on a
workstation. Information is formatted for display or printing in this layer. Codes within the data, such
as tabs or special graphics sequences, are interpreted. Data encryption and translation of other
character sets are also handled in this layer.

Applications access the underlying network services using defined procedures in this layer. The
application layer is used to define a range of applications that handle file transfers, terminal sessions,
and message exchanges. Data starts at the application and presentation layers, where a user works
with a network application, such as an electronic mail program. Requests for services are passed
through the presentation layer to the session layer which begins the process of packetizing the
information. A connection-oriented communication session may be opened between the two systems
to provide reliable transmissions. Once the session is established, protocol layers begin exchanging
information as appropriate.

Packet

A packet is a package of data that is exchanged between devices over a data communications link.
Data exchanged between devices may include messages and commands, control codes for
managing the session, and data. Information is placed in packets by various communications
subsystems of the transmitting system, then framed into a serial bit-stream and sent across the
communications link. One of the main reasons for packetizing and framing information is that errors
on the communication link only affect a small, discernible part of the transmission, which is easily
retransmitted.

The process starts at the application layer. An application in one computer has some information to
send to another computer. The information is sent down through the protocol stack, across the wire,
and up through the protocol stack of the other computer. This information takes the form of a protocol
data unit (PDU). As the PDU moves through the layers of the sending computer, each layer attaches
specific information to the PDU that is relevant to the protocols in that layer. This attached information
is destined for the peer layer in the receiving computer. For example, the transport layer in the
sending computer adds a sequence number to the PDU. This sequence number is read by the
transport layer in the receiving computer to resequence the packets.

The communication protocol defines the packet structure and the networking system in use and
defines the frame structure for bit-stream transmission. Each protocol layer attaches information
destined for its peer layer in the other computer. When the PDU reaches the physical layer, it is
transmitted as a stream of bits. On copper wire, the bit-streams take the form of voltage level
changes that represent binary ones and zeros. The data-link layer places the PDU in one or more
frames and uses a media access method (such as CSMA/CD or token) to gain access to the
transmission media. The PDU might be subdivided into a number of separately addressed frames.
The frame format is defined by the network in use. For example, Ethernet defines frames that can
hold up to 1,500 bytes of packet data.

In general, a packet is a collection of information that contains data (payload) and headers (pilot).
Headers include the source and destination address as well as control information to handle errors
and keep packets flowing properly. Each packet is a separate block of information that can have a

Summary of Contents for MultiFRAD 200 Series

Page 1: ...Router Two Port Frame Relay Access Device MultiFRAD 200 Series Model FR2201 User Guide...

Page 2: ...anges from time to time in the content hereof without obligation of Multi Tech Systems Inc to notify any person or organization of such revisions or changes Record of Revisions Revision Description A...

Page 3: ...nfiguration 28 Setup Menu 28 IP Setup 29 IPX Setup 31 Spanning Tree Setup 33 Statistics 34 IP Statistics 35 IPX Port Statistics 36 STP Spanning Tree Port Statistics 36 SNMP Statistics 37 WAN Statistic...

Page 4: ...formation 57 Contacting Tech Support via E mail 57 Service 58 The Multi Tech BBS 59 To log on to the Multi Tech BBS 59 To Download a file 59 About CompuServe 60 About the Internet 60 About the Multi T...

Page 5: ...Router Two Port Frame Relay Access Device Chapter 1 Introduction and Description...

Page 6: ...elay network the MultiFRAD strips away the frame relay control information so the target device receives the data packaged in its original form Since frame relay networks use shared resources they typ...

Page 7: ...ns are available and are described in this chapter Chapter 4 MultiFRAD Software Chapter 4 describes the MultiFRAD software from an applications approach and includes examples of possible uses Chapter...

Page 8: ...twork XMT Transmit indicator blinks when packets are being transmitted to the local area network COL Collision indicator lights when a collision is in progress that is when two nodes are transmitting...

Page 9: ...C The data channels can be either RS232C or V 35 If a V 35 connection is desired then the internal shunt for that channel must be physically moved from its default RS232 position to the V 35 position...

Page 10: ...tion Channel 1 V 35 Shunt Position Channel 2 V 35 Shunt Position Figure 1 3 Shunts The MultiFRAD has separate shunts for the trunk and both data channels Both the default RS232 Shunt Position and the...

Page 11: ...terframe timer Special APSM mode to allow Data port and LAN traffic muxing over a single PVC Ethernet Port Routing Protocols IP and IPX and bridging all others Ethernet Interface 10Base T twisted pair...

Page 12: ...12 MultiFRAD II User Guide...

Page 13: ...Router Two Port Frame Relay Access Device Chapter 2 Installation...

Page 14: ...ing your MultiFRAD Remove all items from the box Your shipping box should contain the MultiFRAD a power supply various cables software and manual disks and a MultiFRAD Model FR2201 Quick Start Guide I...

Page 15: ...ion POWER COMMAND PORT TRUNK RS232 V 35 CHANNEL 2 CHANNEL 1 AUI 10BASE T ETHERNET Figure 2 2 Cable Connections 2 Connect one end of an DB25 female cable to the Trunk connector Figure 2 2 Connect the o...

Page 16: ...16 MultiFRAD II User Guide...

Page 17: ...Router Two Port Frame Relay Access Device Chapter 3 Software Loading and Configuration...

Page 18: ...ccess Run by clicking the File menu in Program Manager and then click Run In the Run dialog box type a setup or b setup depending on the letter of your disk drive in the Command Line field and then cl...

Page 19: ...e displayed The On Line Help system provides detailed explanations of each dialog box and option To access Help click the button on the dialog box for which you need additional information If your net...

Page 20: ...number is the same as the MultiFRAD on the other end of the link The WAN network number has to be assigned by the Network Administrator and must be unique throughout the entire internetwork Note The...

Page 21: ...ecting to an Asynchronous data device select Asynchronous then select the appropriate maximum Speed from the drop down list Refer to the user documentation for the parameters of the data device 24 If...

Page 22: ...tep 28 27 If you enabled Frame Relay in the WAN Ports Default Setup dialog box the Frame Relay DLCI Default Setup dialog box is displayed with all the groups inactive Click OK to continue When your Mu...

Page 23: ...ration icon in the MultiFRAD 2000 Program Group The main Setup dialog box is displayed Win95 NT users from your desktop click Programs MultiFRAD 2000 then MultiFRAD Configuration The main Setup dialog...

Page 24: ...and enter the Be value your service provider supplied for this DLCI The Compression option may be useful at low link speeds however do not use this feature with a high speed link The Management Type i...

Page 25: ...Router Two Port Frame Relay Access Device Chapter 4 MultiFRAD Software...

Page 26: ...in Windows 95 NT click the Start button point to Programs then MultiFRAD 2000 and click MultiFRAD Configuration You may also start the MultiFRAD Configuration from My Computer by selecting the mf2000...

Page 27: ...Although parameters can be changed be sure to note the current status of the software before making any alterations When you installed the MultiFRAD software you selected to configure the port as eith...

Page 28: ...ormation regarding the status of events such as the type of frame relay management selected and which PVCs are active The status bar located at the bottom of the Setup menu displays MultiFRAD status e...

Page 29: ...s that was established during software installation From the Ethernet IP Setup dialog box you can switch to the to either the WAN IP Setup dialog box or the Advanced IP Setup dialog box by clicking th...

Page 30: ...lay Agent should be enabled if there are DHCP clients on the LAN segment of the MultiFRAD The IP address of either the DHCP server or the next known DHCP relay agent needs to be entered in the Server...

Page 31: ...ou to enable or disable IPX routing on the WAN port change the network number for the WAN port enable or disable NetBIOS change the default RIP and SAP timers and optimize the bandwidth If the WAN por...

Page 32: ...f Ethernet network numbers specifies the broadcast name of the MultiFRAD and defines any IPX filtering by filter type port number and IPX address If bridging of IPX packets is desired IPX routing must...

Page 33: ...hich the MultiFRAD does not support The MultiFRAD defaults with one logical WAN port mapped to a DLCI It is not necessary to map this port to a DLCI however care should be taken if an additional logic...

Page 34: ...anagement frames approximately every ten seconds trying to establish communication with the provider s switch If the unit is sending frames but not receiving any this may be an indication of a problem...

Page 35: ...where the reliability measures are not assumed by other layers It is connection oriented and has a full range of services These statistics are primarily informational and their use as a troubleshootin...

Page 36: ...ne which one is being used by the amount of packets transmitted and received STP Spanning Tree Port Statistics The STP Spanning Tree Port Statistics dialog box displays information regarding the selec...

Page 37: ...d the network management systems The managed device is the network device such as a router The agent is the network management software module residing in the managed device The network management sys...

Page 38: ...ry from the MultiFRAD before the next status enquiry was sent by default there are 10 seconds between status enquiries A Sequence Number Error means the sequence numbers in a received status response...

Page 39: ...window shows the statistics for both data channels If you highlight and double click Port 1 or Port 2 on this screen you will display another screen of channel statistics and various hardware signals...

Page 40: ...and the modem type chosen in this field If the Frame Relay Device Driver is enabled the MultiFRAD encapsulates data on its composite link for transmission over a frame relay network Enabling this dev...

Page 41: ...ote if there are no entries in the User database any User Name and Password combination from a peer will be authenticated For MultiFRAD to MultiFRAD connections authentication normally is not used and...

Page 42: ...ds to a lower value e g 5 seconds will increase the frequency of those verifications 2 Change the Full Status Enquiry Interval to affect how often DCLI Status is updated This parameter defines how oft...

Page 43: ...ialog box The dialog box will then change to the mapping of that DLCI To add a new DLCI that has not been auto detected click the New button and the Frame Relay New DLCI dialog box is displayed To add...

Page 44: ...surement Interval and can limit throughput to either the CIR Adhere to CIR or the CIR plus the Be Adhere to CIR Be The Congestion Management setting selects whether the MultiFRAD should stop sending d...

Page 45: ...s say we also want to map a data channel to DLCI 17 The data ports that are already mapped to other DLCIs are grayed out In our example lets map data port 3 to DLCI 17 Simply click Port 3 in the Data...

Page 46: ...gure Synchronous then configure the MultiFRAD to match your synchronous device The Data Port Configuration dialog box also enables you to configure both data channels independently For example Port 1...

Page 47: ...Router Two Port Frame Relay Access Device Chapter 5 Remote Configuration and Management...

Page 48: ...Remote Configuration Procedure in this chapter to configure a remote MultiFRAD Modem Based Remote Configuration Procedure 1 At the remote site remove the serial cable from the PC to the Command Port c...

Page 49: ...s the dialog box of the remote MultiFRAD Refer to Chapter 4 for a description of each dialog box For a detailed description of each field within a dialog box refer to the on line helps provided within...

Page 50: ...ware on the local PC and at the Windows Program Manager screen and run the Configuration Port Setup program Windows 3 1x Double click the Configuration Port Setup Icon in the MultiFRAD program group W...

Page 51: ...as a built in Telnet Server for access through Telnet clients A typical Telnet client is allowed to configure the MultiFRAD and its data ports In addition the MultiFRAD can be remotely accessed and co...

Page 52: ...Applications Setup dialog box in the MultiFRAD Software once you choose an option from the MultiFRAD Telnet Server dialog box you must enter your password before your choice is accepted MultiFRAD Conf...

Page 53: ...After selecting Remote User Database type 2 Enter from the MultiFRAD Setup menu type A Enter to add a new user to the database The following list of options is displayed By selecting and configuring t...

Page 54: ...he IP Address of the unit in the address line of your web browser In this example the IP address is 192 168 2 14 Click the word Login to gain access to the MultiFRAD The following screen appears Enter...

Page 55: ...Router Two Port Frame Relay Access Device Chapter 6 Warranty Service and Tech Support...

Page 56: ...products which have been damaged by lightning storms water or power surges or which have been neglected altered abused used for a purpose other than the one for which they were manufactured repaired...

Page 57: ...D including LED indicators screen messages diagnostic test results DIP Switch settings problems with a specific application etc Use the space below to note the status _________________________________...

Page 58: ...ment if the MultiFRAD is out of warranty Check with your technical support specialist for the standard repair charge for your MultiFRAD if possible note the name of the technical support specialist wi...

Page 59: ...he password 4 Answer Y or N to the automatic logoff question 5 Select a file transfer protocol by typing the indicated letter such as Z for Zmodem the recommended protocol 6 If you select Zmodem the t...

Page 60: ...es a Web site at http www multitech com and an ftp site at ftp ftp multitech com The ftp server mirrors the Multi Tech BBS About the Multi Tech Fax Back Service Multi Tech s fax back system provides 2...

Page 61: ...Router Two Port Frame Relay Access Device Appendixes...

Page 62: ...4 5 6 7 8 10Base T RJ 45 AUI DB 15 Pin Circuit Signal Name Pin Circuit Signal Name 1 TD Data Transmit Positive 1 CO S Control In Circuit Shield 2 TD Data Transmit Negative 2 CI Control In Positive 3 R...

Page 63: ...NAL TX CLOCK A RECEIVE CLOCK A EXTERNAL TX CLOCK B RECEIVE CLOCK B TRANSMIT CLOCK A TRANSMIT CLOCK B The MultiFRAD RS232C interface circuits have been designed to meet the electrical specificaitons gi...

Page 64: ...Cable PIN NO 1 2 3 4 5 6 7 8 20 22 25 1 2 3 4 5 6 7 8 20 22 25 To DCE Device Communication Device i e Modem FRAME GROUND TRANSMIT DATA TX RECEIVE DATA RX REQUEST TO SEND RTS CLEAR TO SEND CTS SIGNAL G...

Page 65: ...nstallation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communication...

Page 66: ...dled at that layer creating a new packet within a packet This package is then passed down to the next layer and the process continues Each layer adds information to the message packet and this informa...

Page 67: ...etween devices over a data communications link Data exchanged between devices may include messages and commands control codes for managing the session and data Information is placed in packets by vari...

Page 68: ...d NetWare networks each network segment has its own address which is used for routing purposes and differentiate each segment from the others In TCP IP networks such as the Internet every node has a n...

Page 69: ...rks use the first byte of the IP address for the network number and the remaining three bytes for the host number The first byte may have any value from one to 127 Class B networks use the first two b...

Page 70: ...70 MultiFRAD II User Guide...

Page 71: ...Router Two Port Frame Relay Access Device Glossary...

Page 72: ...8 possible characters The extended ASCII file provides 255 characters Asynchronous Transfer Mode ATM A very high speed method of transmission that uses fixed size cells of 53 bytes to transfer informa...

Page 73: ...cess control protocols A bridge forwards a frame to another bridge based on the medium access control MAC address 3 In the connection of local loops channels or rings the equipment and techniques used...

Page 74: ...Mx Port A serial communications port on a PC Congestion A network condition where there is too much data traffic The ITU I 233 standard defines congestion management in terms of speed and burstiness C...

Page 75: ...A software module that interfaces between the Operating System and a specific hardware device i e color monitors printers hard disks etc Also known as a device driver Drop and Insert The process wher...

Page 76: ...enabling ease of access and flat rate calls anywhere in the foreign exchange area Foreign Exchange Office FXO provides local telephone service from a CO outside of foreign to the subscriber s exchange...

Page 77: ...P refers to the global system of interconnecting computers It is a highly distributed protocol each machine only worries about sending data to the next step in the route Internetwork Packet Exchange I...

Page 78: ...Bell system was divided into approximately 161 LATAs The Bell Operating Companies BOCs provide Intra LATA services Local Exchange Carrier LEC The local phone company which provides local i e not long...

Page 79: ...recovery in AMI and B8ZS On Hook The condition of a device which has not accessed a phone line In modem use this is equivalent to a telephone handset that has not been picked up In other words it can...

Page 80: ...a Network PDN A packet switched network that is available to the public for individual subscriber use Typically controlled by a government or a national monopoly Public Switched Telephone Network PSTN...

Page 81: ...ishing maintaining accounting for and terminating a connection between two endpoints e g the user premises and the telco CO Central office signals to the user premises can include ringing dial tone sp...

Page 82: ...urces of data on a T1 line The T1 mux assigns each data source to distinct DS0 time slots within the T1 signal Wide bandwidth signals take more than one time slot Normal voice traffic or 56 64K bps da...

Page 83: ...s comm link to the remote modem and remote digital loopback tests remote modem operation Virtual Circuit A logical connection Used in packet switching wherein a logical connection is established betwe...

Page 84: ...Terminal Equipment 6 Default Setup 27 Download Default Setup 27 Download Firmware 26 E Ethernet 19 EtherNet 10Base T Connector 9 EtherNet AUI Connector 9 EthernetII Type II 20 Excess Burst Rate 24 F F...

Page 85: ...SNMP Statistics 37 STP Spanning Tree Port Statistics 36 WAN Statistics 38 WAN Port Setup 39 Shunts Channels 1 and 2 10 Trunk RS232 10 SNAP 20 SNMP Statistics 37 Software Uninstall 27 Spanning Tree Set...

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