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A hub providing a common termination point for hosts connected to 10Base-T wiring. See also 10Base-T.
A MAX TNT card containing four 10Base-T Ethernet interfaces. The card provides full 10-Mbps access to up to four Ethernet networks. Compare with 10/100-Mbps Ethernet card, Ethernet-2 card. See also 10Base-T.
A MAX TNT card containing four 10Base-T Ethernet interfaces and one 100Base-T Ethernet interface. The card provides full 10-Mbps access to up to four Ethernet networks, and 100-Mbps access to a single Ethernet network. Compare with 10-Mbps Ethernet card, Ethernet-2 card. See also 10Base-T, 100Base-T.
The 802.3 IEEE standard for operating a 100-Mbps Ethernet network. It differs from the 10Base-T standard by requiring higher-grade cable or more wiring pairs, and by supporting cable lengths that are only a tenth as long as 10Base-T cable lengths. See also 10Base-T.
An IEEE protocol specification for the Media Access Control (MAC) header of an IPX frame in NetWare 3.12 or later. An 802.2 frame contains the Logical Link Control (LLC) header in addition to the MAC header. Compare with 802.3, Ethernet II, SNAP. See also IPX frame, LLC, MAC.
An IEEE protocol specification for the Media Access Control (MAC) header of an IPX frame in NetWare 3.11 or earlier. An 802.3 frame does not contain the Logical Link Control (LLC) header in addition to the MAC header. The 802.3 frame is also called Raw 802.3. Compare with 802.2, Ethernet II, SNAP. See also IPX frame, LLC, MAC.
An IEEE protocol specification for the physical layer and Media Access Control (MAC) sublayer of a token-ring topology. 802.5 implements token passing over Shielded Twisted Pair (STP) cabling, and offers data rates of 4 or 16 Mbps. See also STP cable.
Area Border Router. An ABR is an Open Shortest Path First (OSPF) router that belongs to both a regular area and the backbone area. See also area, backbone area, OSPF.
A packet sent by the RADIUS server to inform the MAX TNT that a client's request for access has been granted. See also RADIUS server.
A request for the user to enter a password in a hand-held token card. The token-card server sends the Access-Challenge packet through the RADIUS server and the MAX TNT to the user. See also RADIUS server, token card, token-card server.
A response from the RADIUS server informing the MAX TNT that it has accepted a new password. See also RADIUS server.
A response from the RADIUS server informing the MAX TNT that it has rejected a new password. See also RADIUS server.
A password-change request that the MAX TNT sends to the RADIUS server. See also RADIUS server.
A packet the RADIUS server sends to inform the MAX TNT that it has not granted a client's request for access. The RADIUS server sends an Access-Reject packet if the user enters an unknown user name, fails to enter the correct password, or enters an expired password. See also RADIUS server.
A packet that the MAX TNT sends to the RADIUS server on behalf of a client attempting to establish a connection. See also RADIUS server.
See ASG.
A way to log information in RADIUS about Start session, Stop session, and Failure-to-start session events. When the MAX TNT recognizes one of these events, it sends an accounting request to RADIUS. When the accounting server receives the request, it combines the information into a record and timestamps it. Each type of accounting record contains attributes associated with an event type, and can show the number of packets the MAX TNT transmitted and received, the protocol in use, the user name and IP address of the client, and other session information. See also accounting server, Failure-to-start session, proxy RADIUS accounting, Start session, Stop session.
See AFS record.
A request for accounting information. The MAX TNT sends an Accounting-Request packet to the RADIUS accounting server. See also accounting server, RADIUS.
A packet containing accounting information. The RADIUS accounting server sends an Accounting-Response packet to the MAX TNT. See also accounting server, RADIUS.
The RADIUS daemon with accounting enabled. See also See ASG., RADIUS daemon.
A form of token-card authentication in which RADIUS forwards a connection request to a Security Dynamics ACE/Server. The ACE/Server sends an Access-Challenge packet back through the RADIUS server and the MAX TNT to the user dialing in. The user sees the challenge message, obtains the current token from his or her card, and enters the token. (A token is a type of password.)
The token travels back through the MAX TNT and the RADIUS server to the ACE/Server. The ACE/Server sends a response to the RADIUS server, specifying whether the user has entered the proper user name and token. If the user enters an incorrect token, the ACE/Server returns another challenge, and the user can again attempt to enter the correct token. The server sends up to three challenges. After three incorrect tries, the MAX TNT terminates the call.
See also ACE token, authentication, RADIUS server, token, token card, token-card authentication, token-card server.
A randomly generated access code that a user obtains from a SecurID token card. The code changes every 60 seconds. See also ACE authentication, token card.
Address Complete Message. An ACM is sent between an Access SS7 Gateway (ASG) and the SS7 network. For an incoming call, the ASG sends an ACM to the SS7 network in order to acknowledge that it has received the information required to route the call. For an outgoing call, the SS7 network sends an ACM to the ASG in order to acknowledge that it has received the required information. See also ASG, SS7 Carrier Signaling.
A device that amplifies transmissions signals on a network, enabling them to be transmitted over a much greater distances than is possible with a passive hub. Compare with passive hub, smart hub. See also hub.
See ACM.
A method of mapping a logical address (such as an IP address) to a hardware address (such as a MAC address). See also ARP, hardware address, IP address, logical address, MAC address.
See ARP.
A relationship formed between neighboring Open Shortest Path First (OSPF) routers for the purpose of exchanging routing information. An OSPF router dynamically detects its neighboring routers by sending Hello packets to the multicast address AllSPFRouters. It then attempts to form adjacencies (Figure 1).
Figure 1. Adjacency between neighboring routers
Asymmetric Digital Subscriber Line. ADSL is a standard that enables devices attached to twisted-pair copper wiring to transmit data at rates from 1.5 Mbps to 9 Mbps downstream, and 16 kbps to 640 Kbps upstream. ADSL devices can transmit data at distances of up to 18,000 feet. Compare with HDSL, SDSL.
Accounting Fail-Safe record. When a call comes in and RADIUS accounting is in use, the host card first sends a Start record to the shelf controller, which stores it as an AFS record. The host card then sends one or more Start records to the RADIUS accounting server, repeating until it receives an ACK from the server. Similarly, when the call clears, the host card sends a Stop record to the shelf controller, which causes it to delete the AFS record for that session. The host card then sends the accounting server Stop records until it receives an ACK from the server. See also See ASG., accounting server, Checkpoint record, proxy RADIUS accounting, Start record, Stop record.
A network device (such as the MAX TNT) that provides Simple Network Management Protocol (SNMP) information to a manager application running on another computer. The agent and manager share a database of information, called the Management Information Base (MIB). The manager polls the agent for information at regular intervals. When an unusual system event occurs, the agent can use a message called a traps-PDU to send unsolicited information to the manager. See also manager, MIB, SNMP, traps-PDU.
Alarm Indication Signal. An AIS is a signal that a device sends in order to take a T1 line, DS3 line, or DS2 stream out of service. See also DS3 line, T1 line.
See AIS.
An ITU-T standard for sampling data by means of Pulse Coded Modulation (PCM). A-Law is most commonly used outside of North America and Japan. Compare with U-Law. See also PCM.
See AMI.
Average Line Utilization. ALU is the average amount of bandwidth used on a line over a user-specified period of time. The MAX TNT uses ALU when determining whether to add or subtract bandwidth from a multichannel call. See also DBA.
See ANSI.
Alternate Mark Inversion. Used on T1 lines, AMI is a signaling method in which the 1 bits have alternating priority. See also T1 line.
Data that can change continuously and have any value in a range. Examples of analog data are the time of day represented by clock hands, and the temperature represented by a liquid thermometer. Compare with digital data. See also analog signal.
A line that transmits data by means of an analog signal. See also analog signal.
A test that checks whether the modem or Data Terminal Equipment (DTE) is causing errors in data transmission. During an analog loopback, the system sends data between the local modem and the local DTE. Errors in transmission indicate a problem with the modem, DTE, or the interface between them. Compare with digital loopback. See also local loopback, loopback, remote loopback.
A V.34bis MAX TNT card that supports users who do not have access to digital services. Each 36-port Analog Modem card occupies two slots on the MAX TNT, and supports analog connections at rates of up to 33.6 Kbps. A single-shelf MAX TNT can include up to seven Analog Modem cards for 252 remote analog connections. Compare with Digital Modem card, Series56 Digital Modem card. See also analog data, V.34bis.
A type of signal that encodes data transmitted over wire or through the air, commonly represented as an oscillating wave. An analog signal can transmit analog or digital data. It takes any value in a range, and changes smoothly between values. A radio station sends analog music data using analog signals, while a modem transmits digital data using analog signals. Compare with digital signal. See also analog data.
Automatic Number Identification. ANI is a mechanism that informs the called party of the calling party's phone number. Though ANI is often thought of as an ISDN feature, it is actually part of Signaling System 7, and distinct from ISDN. See also CLID authentication, Signaling System 7.
Answer Message. An ANM is sent between an Access SS7 Gateway (ASG) and the SS7 network. For an incoming call, the ASG sends an ANM to inform the SS7 network that the path is set up to divert the Internet call. For an outgoing call, the SS7 network send an ANM to the ASG, indicating that the Central Office (CO) switch is ready to receive the call at the identified circuit. See also ASG, SS7 Carrier Signaling.
American National Standards Institute. ANSI creates standards for networking and communications. It is the U.S. representative to the International Standards Organization (ISO). See also ISO.
A profile that sets baseline values to determine how the MAX TNT evaluates incoming calls before it accepts them. If the call does not comply with the Answer-Defaults settings, the unit rejects the call without answering it. Therefore, you must check the Answer-Defaults values to make sure they are appropriate for your site.
The MAX TNT applies the Answer-Defaults values before it routes the call to a digital modem or High-Level Data Link Control (HDLC) channel for processing, and before it locates a Connection profile or RADIUS user profile. If the caller's profile contains a parameter or attribute similar to one in the Answer-Defaults profile, but the caller's setting specifies a different value, the MAX TNT uses the value in the Connection profile or RADIUS user profile to build the session.
By default, the Answer-Defaults profile enables all types of encapsulation and routing, and the basic call-setup parameters use the lowest-common-denominator settings. The default settings are appropriate for many sites. You might want to change the settings in order to finetune the criteria by which the MAX TNT accepts calls or determines how much bandwidth is accessible to Multilink Protocol (MP) or Multilink Protocol Plus (MP+) sessions. See also Connection profile, HDLC channel, MP, MP+.
See ANM.
Apple's protocol suite that enables Macintosh computers to function on a network. AppleTalk works with such network operating systems as TOPS (from Sun Microsystems) and AppleShare. See also AppleTalk router, AppleTalk routing, ARA.
See ARA.
A device that sends AppleTalk packets from a source to a destination by various paths. See also AppleTalk, AppleTalk routing, ARA.
A routing configuration in which Macintosh computers can share files and services on a network. A MAX TNT configured for AppleTalk routing can receive dial-in connections from AppleTalk Remote Access (ARA) client software, Point-to-Point Protocol (PPP) dial-in software that supports AppleTalk, and AppleTalk-enabled Ascend units.
Figure 2 shows a MAX TNT that routes AppleTalk between WAN interfaces and a local AppleTalk interface.
Figure 2. Routing AppleTalk between LAN and WAN interfaces
The highest layer of the OSI Reference Model. The Application layer provides applications with access to the network. File transfer, email, and network management software are examples of Application-layer programs. Protocols such as File Transfer Protocol (FTP), Rlogin, Simple Network Management Protocol (SNMP), and Telnet provide Application-layer services. See also FTP, OSI Reference Model, Rlogin, SNMP, Telnet.
AppleTalk Remote Access. ARA enables a remote Macintosh workstation to gain access to an IP network. You can use ARA over a modem or V.120 connection, or over synchronous PPP when the calling unit is an AppleTalk-enabled Ascend unit. Clients can dial in using ARA client software or a PPP dialer that supports AppleTalk. See also AppleTalk, AppleTalk router, AppleTalk routing, modem, PPP, V.120.
Attached Resource Computer Network. ARCnet is a baseband network architecture with a transmission rate of up to 2.5 Mbps. Because it is relatively inexpensive and easy to set up, ARCnet is typically used for smaller networks.
A portion of an Open Shortest Path First (OSPF) Autonomous System (AS). An area acts as its own network. All area-specific routing information stays within the area, all routers within an area have a synchronized link-state database, and each database within an area is unique. On the MAX TNT, an area number uses dotted decimal notation. It is not an IP address.
To tie the areas together, some routers belong to a backbone area and one other type of area. These routers are called Area Border Routers (ABRs). In Figure 3, all of the routers are ABRs.
Figure 3. Dividing an AS into areas
See ABR.
Address Resolution Protocol. ARP is a protocol in the TCP/IP protocol suite. By mapping an IP address to a physical (hardware) address, ARP enables a unit to identify hosts on an Ethernet LAN. See also Ethernet, proxy ARP, TCP/IP.
Autonomous System. An AS is a group of Open Shortest Path First (OSPF) routers that exchange information, typically under the control of one company. An AS can include a large number of networks, all of which share the same AS number. All information exchanged within the AS is interior. Exterior protocols, such as Exterior Gateway Protocol (EGP), exchange routing information between one AS and another. Using an EGP, the MAX TNT imports external routes into its OSPF database and flags them as ASE (Autonomous System External). See also ASE, EGP, external route, OSPF, router.
Autonomous System Border Router. An ASBR is an Open Shortest Path First (OSPF) router that handles communication between Autonomous Systems (AS) by using an Exterior Gateway Protocol (EGP), as shown in Figure 4.
Figure 4. Autonomous System Border Routers (ASBRs)
A packet containing a notification that the MAX TNT has started up, or a making a request for the RADIUS server to record the number of open sessions. See also RADIUS server.
A response from the RADIUS server reporting that the MAX TNT has started up, or specifying the number of open sessions and informing the MAX TNT that the server has received and recorded the MAX TNT unit's ID. See also RADIUS server.
A response from the RADIUS server informing the MAX TNT that it should request access again, but with the next Personal Identification Number (PIN) in the sequence. See also RADIUS server.
A response from the RADIUS server informing the MAX TNT that it should request access again, but with the next password in the sequence. See also RADIUS server.
A response from RADIUS server to the MAX TNT, indicating that the password the user entered matches the one in the user profile, but has expired. (That is, the Access-Request packet sent a valid but expired password.) See also
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