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1862 VoIP IAD User’s Guide 

 

 

 

 

Chapter 10 Specifications 

WAN Interface  

ADSL Standard 

 

ANSI T1.413 Issue 2, ITU-T G.992.1, ITU-T G.992.2     

Data rate 

Downstream:  Up to 11 Mbps 

 

Upstream:   

1 Mbps           

LAN Interface  

Ethernet Standard  

 

IEEE 802.3 10/100 Base-T,     

USB     Standard                     V 1.1   

Analog Interface    

FXS x 1     

FXO x 1(Built-in Microfilter)      

ATM Attributes         

RFC 2364, RFC 2684 (RFC 1483) Bridge; RFC 2684 (RFC 1483) Route; RFC 2516; RFC 1577   

VCs    

 

 

8        

AAL type 

 

 

AAL5       

ATM service class 

 

UBR/CBR/VBR   

ATM UNI support 

 

UNI3.1/4.0     

OAM F4/F5   

 

Yes    

Management  

SNMP, ILMI 4.0, Telnet, Web-based management, Configuration backup and restoration             

Software upgrade via TFTP client or FTP server 

 

Bridge Functions  

Transparent bridging and learning   IEEE 802.1d   

Spanning Tree Algorithm 

Yes            

QOS   

 

 

Yes       

Routing Functions      

Static route, RIP, and RIPv2, NAT/PAT, DHCP Client/Server/Relay, DNS, ARP   

  

65

 

Содержание 1862

Страница 1: ...1862 VoIP IAD MGCP User s Guide Document Number 1862 A2 GB20 00 November 2004 ...

Страница 2: ...the Paradyne World Wide Web site at www paradyne com Be sure to register your warranty at www paradyne com warranty Telephone Call our automated system to receive current information by fax or to speak with a company representative Within the U S A call 1 800 870 2221 Outside the U S A call 1 727 530 2340 Document Feedback We welcome your comments and suggestions about this document Please mail th...

Страница 3: ...omer Use a UL Listed CSA certified minimum No 24 AWG line cord for connection to the Digital Subscriber Line DSL network 6 When installed in the final configuration the product must comply with the applicable Safety Standards and regulatory requirements of the country in which it is installed If necessary consult with the appropriate regulatory agencies and inspection authorities to ensure complia...

Страница 4: ...terference and 2 this device must accept any interference received including interference that may cause undesired operation The authority to operate this equipment is conditioned by the requirement that no modifications will be made to the equipment unless the changes or modifications are expressly approved by the responsible party This equipment has been tested and found to comply with the limit...

Страница 5: ...he total RENs contact the local Telephone Company The REN for this product is part of the product identifier that has the format US AAAEQ TXXXX The digits represented by are the REN without a decimal point For example 03 represents a REN of 0 3 If the modem causes harm to the telephone network the Telephone Company will notify you in advance that temporary discontinuance of service may be required...

Страница 6: ...nt is labeled on the equipment The REN assigned to each terminal equipment provides an indication of the maximum number of terminals allowed to be connected to a telephone interface The termination on an interface may consist of any combination of devices subject only to the requirement that the sum of the Ringer Equivalence Numbers of all the devices does not exceed five If your equipment is in n...

Страница 7: ...ON 22 CHAPTER 5 BASIC CONFIGURATION 25 5 1 ACCESS CONTROL 25 5 2 WAN SETUP 28 5 3 LAN IP ADDRESS 35 5 4 ROUTING 36 5 5 SAVE 39 5 6 REBOOT 39 5 7 RETRIEVE DEFAULT SETTINGS 40 CHAPTER 6 ADVANCED CONFIGURATION 41 6 1 CONFIGURE 41 6 2 VCC 44 6 3 ADSL MODE 49 6 4 DHCP 49 6 5 DHCP RELAY 52 6 6 NAT 53 CHAPTER 7 PERFORMANCE MONITORING 55 7 1 ADSL LINK STATUS 55 7 2 SYSTEM STATISTICS 56 7 3 ATM STATISTICS ...

Страница 8: ...1862 VoIP IAD User s Guide 8 ...

Страница 9: ...d applications and explains the functions of the Front panel LED indicators 1 1 Product Overview The 1862 is a powerful VoIP Integrated Access Device IAD providing predictable real time toll quality voice over the Internet The 1862 VOIP IAD is designed for residential and business users who need to integrate ADSL and VoIP technologies With ADSL broadband technology the 1862 VOIP IAD offers users e...

Страница 10: ...rnet Calls with Low Charges Use Just One IP Address to Access the Internet Over Your Entire Network Configurable Through Your Networked PC s Web Browser Remote Administration and Remote Firmware Upgrades Over the Internet Block Specific External and Internal Internet Access with Packet Filtering Supports PPTP L2TP and IpSec Pass Through Supports Lifeline POTS for Emergencies 10 ...

Страница 11: ...blished Flashing The ADSL link is training Off The ADSL link is not established Red Flashing An alarm has occurred ALARM Off Normal operating status Green On A FX0 link is established and busy with a call Off A FX0 link is established and idle FX0 Green Flashing Trying to connect to the Call Agent VoIP Service Center Green On A FXS link is established and busy with a call Off A FXS link is establi...

Страница 12: ...1862 VoIP IAD User s Guide Green Flashing Activity over the USB link 12 ...

Страница 13: ... FXS port for VoIP service 4 Connect the USB port to your PC with a standard USB cable 5 Connect the LAN port to a PC or hub with an RJ45 cable 6 Connect the Line port to the ADSL wall outlet a POTS splitter or micro filter with an RJ11 connector cable Consult your Internet Service Provider ISP 7 Turn on the power switch on the rear panel Note 1 If the device fails to power on or it malfunctions f...

Страница 14: ...fore installing the software To install the USB driver complete the following steps STEP 1 Insert the CD ROM disc for the 1862 VoIP IAD STEP 2 Browse the CD ROM and open the USB Driver Folder Double click on on SETUP EXE STEP 3 Click on the Next button and the Wizard will proceed to install the driver 14 ...

Страница 15: ...1862 VoIP IAD User s Guide STEP 4 An installation successful message pops up when the installation is complete STEP 5 Connect your IAD to the USB port of the PC 15 ...

Страница 16: ...river by completing the following steps STEP 1 Click on the Windows Start button and go to Programs Drivers Comtrend CT 6xx Click on on Uninstall STEP 2 Click on OK when you are prompted to confirm the action STEP 3 When prompted by the message shown below disconnect the USB cable from your PC and click on on the OK button 16 ...

Страница 17: ...1862 VoIP IAD User s Guide STEP 4 When the driver is removed a complete message pops up Click on Finish to close the window 17 ...

Страница 18: ... hear a special call waiting tone At this moment you can press to accept the FXO call then press again to return to the VoIP call 2 4 1 Emergency call function 200 configurable emergency call numbers are provided These emergency calls can automatically connect to a French Telecom PSTN service Complete the following procedures to setup the emergency call numbers root home mgcp root mgcp emgcycall 0...

Страница 19: ...ided with user name root and password 1234 For security purposes you should change the default password the first time you log in 3 1 IP Address To log on to the device using a web browser your workstation and the device should both be on the same network segment The default IP address is 192 168 1 1 You can modify the IP address of your PC by following these steps STEP 1 In Windows go to Control ...

Страница 20: ...he steps below STEP1 Start your web browser STEP 2 Type the IP address for the IAD in the Web address field For example if the IP address is 192 168 1 1 type http 192 168 1 1 STEP 3 You will be prompted to enter your user name and password Type the user name and password The default user name is root and password 1234 The user name and password are case sensitive Note The user name and password ma...

Страница 21: ... VoIP IAD User s Guide STEP 4 After successfully logging in you will reach the main menu On this framed window a menu of hyperlinks is displayed on the left There are three categories Basic VoIP Advanced 21 ...

Страница 22: ...ication configured by you We will use the scenario illustrated in the following diagram to explain MGCP configuration STEP 1 Select MGCP on the VoIP menu the current configuration of the IAD is displayed STEP 2 Select which endpoint you want to modify and click on on Update aaln 1 is the endpoint name for FXS 22 ...

Страница 23: ...ateway Domain Name The domain name of the Gateway For example mg1 Port Number The gateway port number for MGCP Call Signaling control For example 2427 Interface Name The gateway binding interface for MGCP Call Signaling control or example eth0 Example RQNT 1201 aaln 2 mta1 MGCP 1 0 N ca ca1 whatever net 5678 X 0123456789AC R l hd N S l rg 23 ...

Страница 24: ...o a DNS lookup until it receives a valid IP address translation from the DNS server and then it will send RSIP to this IP address Note 2 If you choose Domain Name type the IP address field will display the DNS lookup result automatically Endpoint Endpoint Name The endpoint name of the telephone port in the configuration for example aaln 2 for port 2 Status The Endpoint status setting UP If you cho...

Страница 25: ...cess Control on the menu bar On the Access Control screen you can add modify or delete users 5 1 1 Change the Password To modify the password click on on Access Control on the menu bar Select the applicable User and click on on Change Password On the Change Password screen type the old password and type the new password twice Click on Apply to submit the settings If you change the password make su...

Страница 26: ...services Permissions Select Ordinary or Administration user permission 5 1 3 Modify User To modify a User from the list of users complete the following steps STEP 1 Click on Access Control on the menu bar STEP 2 Choose a User entry and click on on Modify STEP 3 Change the parameters STEP 4 Click on Apply to submit the settings User Name This field displays the selected user name Authorization Old ...

Страница 27: ...s Select Ordinary or Administration user permission 5 1 4 Delete User To delete a User from the list of users complete the following steps STEP 1 Click on Access Control on the menu bar STEP 2 Choose a User entry and click on on Delete 27 ...

Страница 28: ...ls to be transmitted over the ATM Virtual Circuit VC Multiplexing With VC Multiplexing no link control header is needed as the ATM Virtual Circuit is assumed to be carrying a single protocol Enable NAPT NAPT or Network Address Port Translation is explained further in section 6 5 3 This feature is available for RFC 1483 Routed PPPoE PPPoA and MER Enable DHCP Enables if checked or disables the DHCP ...

Страница 29: ...ocols to be transmitted over the ATM Virtual Circuit With VC Multiplexing no link control header is needed as the ATM Virtual Circuit is assumed to be carrying a single protocol Since the Ethernet packets are bridged the IAD s only responsibility is to pass the Ethernet packets to and from the Internet Service Provider and the local network The IP addresses of the local network are assigned by the...

Страница 30: ...83 Routed To set up the RFC 1483 Routed mode configure the common settings on the top of the page click on on RFC 1483 Routed and configure the specific settings WAN IP address and WAN subnet mask Click on the Add button to add the entry 30 ...

Страница 31: ...own public IP addresses To set up PPPoE click on on PPPoE configure the common fields on the top of the page then following fields Click on on the Add button to add the entry User name Password Used for remote customers to login during dialup Dialing Mode Direct and Auto If the mode is set to AUTO the PPPoE negotiation automatically starts when the system identifies any traffic required to be tran...

Страница 32: ...elds and the following fields Click on the Add button to add the entry User name and Password used for remote customers to login upon dialup PPPoA is manually activated by entering startup commands from the page Advanced Configure PPPoA Authentication defines the authentication code PAP or CHAP 32 ...

Страница 33: ...e RFC 1483 bridged link NAPT function is supported to allow multiple private IP addresses on the LAN to share a public IP address To set up MER service configure the common fields and then enter the IP Address and Subnet Mask under the MER section of the screen Click on the Add button to add the entry 33 ...

Страница 34: ...ay at the bottom of the configuration page STEP 3 Complete the fields below Domain Name User defined Primary DNS server Enter the primary server IP address Secondary DNS server Enter the secondary server IP address that will be used in the event that the primary server IP address fails or is not available Default Gateway The gateway IP address of the IP network STEP 4 Submit the settings by clicki...

Страница 35: ...s is 192 168 1 1 Click on LAN Setup on the menu bar to configure the LAN IP address Type the LAN IP address and subnet mask Click on Apply to submit the settings When the new IP address is applied web interface access will be interrupted Use the new IP address to log in 35 ...

Страница 36: ... the routing functions Routing functions include RIP and static routing You can display the RIP information by clicking on the RIP information button If you wish to change the static routes that are configured you must first click on on the Flush button to remove the current configuration 36 ...

Страница 37: ... the Rip Status field STEP 3 Select a RIP Version Version 1 or Version 2 from the Version field STEP 4 Click on Apply to submit the settings STEP 5 After submitting the new Rip settings the List of Static Routes will be updated to reflect this change A screen similar to the following will be displayed Flag R RIP Route S Static Route C Connect Route 37 ...

Страница 38: ... the following steps STEP 1 Click on Routing Setup on the menu bar STEP 2 Enter parameters for Destination Network ID Subnet Mask and Next Hop IP STEP 3 Click on the ADD button Modify To modify a static route complete the following steps STEP 1 Select the entry you wish to modify from the List of Static Routes STEP 2 Change the parameters STEP 3 Click on the Modify button Delete To delete a static...

Страница 39: ... 5 5 Save To save the settings to Flash click on on Save Reboot on the menu bar In the main window click on on Save 5 6 Reboot To reboot the IAD click on on Save Reboot on the menu bar In the main window click on on on Reboot 39 ...

Страница 40: ...1862 VoIP IAD User s Guide 5 7 Retrieve default settings To retrieve the default settings click on on Erase Reboot on the menu bar In the main window click on on Erase 40 ...

Страница 41: ...1862 VoIP IAD User s Guide Chapter 6 Advanced Configuration 6 1 Configure From the Interface Configure page you can configure LAN and WAN interfaces VCC PPPoE PPPoA DNS Default Gateway and NAT 41 ...

Страница 42: ...UP atm0 to atm7 display the interfaces configured for RFC1483 Bridged mode or RFC 1483 Routed mode Ppp0 to ppp7 display the interfaces configured for PPPoE or PPPoA Parameters Interface Name Displays the interface type IPAddress The IP address of the interface Subnet Mask The subnet mask of the selected interface MAC Address The MAC address of the interface Normally only the LAN interface has the ...

Страница 43: ...eps STEP 1 Click on Interface Configure in the menu bar STEP 2 Click on the DNS and default gateway button at the bottom of the configuration page STEP 3 Complete the fields below Domain Name User defined Primary DNS server Enter the primary server IP address Secondary DNS server Enter the secondary server IP address that will be used in the event that the primary server IP address fails or is not...

Страница 44: ... by clicking on Apply 6 2 VCC This screen lists all current VCC entries in the middle of the screen From this screen you can also List IPoA Delete Encapsulation Add a VCC Delete a VCC and Show VCC quality 6 2 1 List IPoA To list IP over ATM information click on on the IPoA button at the bottom of the screen 44 ...

Страница 45: ...Channel Identifier VCI that identifies this ATM connection The vci is an integer number which can range from 0 to 65 535 Peak Cell rate cells sec Defines the fastest rate a user can send cells to the network It is expressed in units of cells per second Average Cell rate cells sec Defines the maximum sustainable average rate a user can send cells to the network It is expressed in cells per second T...

Страница 46: ...s such as a video stream The user can specify how much bandwidth they wish to reserve Supports time sensitive applications such as voice In these applications the rate at which cells arrive are varied Supports applications that have no constraints on delay and delay variation but still have variable rate and burst traffic characteristics Best effort service that does not require tightly constraine...

Страница 47: ...C entry select the entry from the list of VCCs and then click on on the Delete button at the bottom right of the page 6 2 5 Show VCC quality To view information regarding the VCC quality click on on the Show VCC Quality button at the bottom right of the page 47 ...

Страница 48: ...the entry from the List of PPPoE entries and then click on on the corresponding button at the bottom of the page 6 2 7 PPPoA The PPPoA page can be accessed by clicking on Configure in the Advanced menu bar To start stop delete or set as default a PPPoA entry first select the entry from the List of PPPoA entries and then click on on the corresponding button at the bottom of the page 48 ...

Страница 49: ...ngs 6 4 DHCP The Dynamic Host Configuration Protocol DHCP provides a centralized approach to allocating IP addresses It allows IP addresses to be dynamically assigned on a need to basis from a pool of addresses The DHCP server is disabled by factory default 6 4 1 Enable DHCP STEP 1 Click on DHCP Server Relay on the menu bar There is a default DHCP entry on the screen The default settings are as fo...

Страница 50: ...he first IP address of the address pool in the DHCP server Note the IP address should be in the same subnet as the IAD s LAN IP address End IPAddress The last IP address of the address pool in the DHCP server Note the IP address should be in the same subnet as the IAD s LAN IP address Subnet The subnet mask of the selected interface Netmask The subnet mask of the IP network Gateway The gateway IP ...

Страница 51: ...mplete the following steps STEP 1 Click on DHCP on the menu bar STEP 2 Choose a DHCP entry and click on on Stop 6 4 4 Delete DHCP Server To delete a DHCP Server complete the following steps STEP 1 Click on DHCP on the menu bar STEP 2 Choose a DHCP entry and click on on Delete 51 ...

Страница 52: ...he DHCP Relay To enable the BOOTP DHCP Relay complete the following steps STEP 1 Access the BOOTP DHCP Relay screen by clicking on DHCP on the Advanced Menu and then click on on the DHCP Relay tab STEP 2 In the DHCP Relay field select Enable and enter the IP Address where you want BOOT REQUEST and DHCP packets to be received from clients STEP 3 Click on the Apply button 6 5 2 Disable the BOOTP DHC...

Страница 53: ... local port is the port on the LAN that the virtual server is really accessed The public port is translated to the local port to access to the virtual server Click on the Add button to add a virtual server The following page displays after you click on on Add Public Port Enter the public port number This port will be mapped or redirected to the local port of the virtual on the LAN Internet users a...

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Страница 55: ... the current status of the ADSL line ADSL Mode Shows the ADSL standard that is currently configured The standards are MULTI T1 413 G DMT and G LITE Upstream Upstream data rate negotiated by DSL link Kbit s Downstream Downstream data rate negotiated by DSL link Kbit s Attenuation Current attenuation dB of both near end and far end SNR Margin Current SNR margin dB HEC Count Number of ATM cells recei...

Страница 56: ...s TCP IP and DHCP Lease 7 2 1 Interface Statistics To display the interface statistics click on on the Interface tab located at the top left of the System Statistics screen The Interface Statistics page displays statistics for all interfaces The following information is displayed Field Description Interface Name The name of the interface Admin Status Indicates whether the interface is Up or Down O...

Страница 57: ...umber of Octets bytes transmitted Unicast PktsOut The number of unicast packets transmitted Broadcast PktsOut The number of broadcast packets transmitted Discards Out The number of packets transmitted that were discarded Errors Out The number of outward errors 57 ...

Страница 58: ...User s Guide 7 2 2 TCP IP To view TCP IP statistics click on on the TCP IP tab at the top of the System Statistics page The TCP IP page displays the IP statistics UDP statistics TCP statistics and ICMP statistics 58 ...

Страница 59: ...he System Statistics page The DHCP Lease page shows the PCs that obtained an IP address from the DHCP pool 7 3 ATM statistics Click on ATM Statistics on the menu bar to display the ATM Statistics The ATM Statistics page monitors information for AAL5 and Encapsulation 7 3 1 AAL5 The AAL5 page shows the AAl5 statistics 59 ...

Страница 60: ...oIP IAD User s Guide 7 3 2 Encapsulation Click on the SNDCP tab to display encapsulation statistics This page displays the VCs that are running SNDCP stands for sub network dependency convergency protocol 60 ...

Страница 61: ...on the menu bar STEP 2 Click on the Loopback tab on the Diagnostics screen STEP 3 Enter the following information to run the OAM loopback Flow type F5 SEG Segment to Segment and F5 ETE End to End The SEG loopback is from ATUR to DSLAM The ETE loopback is from ATUR to the ISP RAS VPI and VCI Specify the virtual channel that will run the OAM loopback Loopback ID Type the loopback pattern for the loo...

Страница 62: ...host To access the Ping test screen click on the Ping tab on the Diagnostics screen Enter the Host Name or IP address of the remote terminal and click on Submit to start the ping and display the results The following is an example of the ping result The information is as follows Packets transmitted The number of packets that were transmitted Packets received The number of packets that were receive...

Страница 63: ...me subnet as the IAD 192 168 1 1 STEP 2 Start DOS and enter the menu where the new firmware is installed Example C Upgrade STEP 3 Enter the command ftp 192 168 1 1 IAD s IP address STEP 4 At the USER prompt type root small case STEP 5 At the Password prompt type 1234 STEP 6 After you see the message User Logged in type Bin STEP 7 After you see the message Type set to I type hash STEP 8 After you s...

Страница 64: ...1862 VoIP IAD User s Guide STEP 9 After a moment the file should begin transferring after you see the message Transfer complete the upgrade process is complete 64 ...

Страница 65: ...er ATM Attributes RFC 2364 RFC 2684 RFC 1483 Bridge RFC 2684 RFC 1483 Route RFC 2516 RFC 1577 VCs 8 AAL type AAL5 ATM service class UBR CBR VBR ATM UNI support UNI3 1 4 0 OAM F4 F5 Yes Management SNMP ILMI 4 0 Telnet Web based management Configuration backup and restoration Software upgrade via TFTP client or FTP server Bridge Functions Transparent bridging and learning IEEE 802 1d Spanning Tree A...

Страница 66: ...323 H 323 v3 Codec G 711 G 723 1 G 729ab RTP RFC 1889 SDP RFC 2327 On Off hook Caller ID ETSI based Lifeline POTS Yes Echo cancellation G 168 Silence suppression G 711 G 723 1 G 729ab LED Power LAN ADSL ALARM FXS FXO USB Power External power adapter 110 Vac or 220 Vac Power consumption 8W Environmental Conditions Operating temperature 0 50 degrees Celsius Relative humidity 5 90 non condensing Dime...

Страница 67: ...finition Pin number Definition 1 4 ADSL_TIP 2 5 3 ADSL_RING 6 FXS port RJ11 Pin number Definition Pin number Definition 1 4 TIP 2 5 3 RING 6 LAN Port RJ45 Pin number Definition Pin number Definition 1 Transmit data 5 NC 2 Transmit data 6 Receive data 3 Receive data 7 NC 4 NC 8 NC 67 ...

Страница 68: ...k your PC s TCP IP setup Web login reject Check your password The default user name is root the default password is 1234 The user name and password are case sensitive Check the power adapter and verify if it meets the requirement as stated in Appendix A Specifications Power connections are loose or improperly connected POWER LED is not lit Power source is off 68 ...

Страница 69: ...ican National Standards Institute ASCII American Standard Code for Information Interchange attenuation The loss of power of a transmitted signal as it travels over a wire auto summary A RIP command to restore the default behavior of automatic summarization of subnet routes into network level routes backbone The main circuit that carries data before it is split into extended circuits going to their...

Страница 70: ...es circuit A logical connection between two devices CO Central Office the local telephone exchange also called PSTN COM port A computer s serial communications port CPE Customer Premises Equipment Equipment used by the end user cross talk Undesired coupling of a signal from one circuit or channel to another data rate The speed measured in bits per second that data is transferred over the carrier l...

Страница 71: ...m the PC EOC Embedded Operations Channel An in band channel between DSL devices that operates at the physical layer for administration and maintenance data error control An algorithm used to detect and correct data transmission errors errored second An item in performance measurement report which pertains to a one second period with one or more errored blocks Ethernet address Another name for MAC ...

Страница 72: ...et protocol that allows for the generation of error messages tests packets and information messages related to IP IDSL A form of ISDN DSL using 2B1Q line code IEEE Institute of Electrical and Electronics Engineers IEEE The Institute of Electrical and Electronics Engineers ILMI Interim Local Management Interface Provides ATM layer management between a switch and a client device IP address Internet ...

Страница 73: ...acture and used in PAT protocols MAC Medium Access Control a protocol for determining which device has access to the network at any one time Mbps Megabits per second One megabit is 1 048 576 10242 bits MCU Multi Commercial Unit A commercial building or complex with multiple tenants MDU Multi Dwelling Unit A residential building with multiple tenants MIB II MIB Release 2 An update of the MIB standa...

Страница 74: ...allation point to point connection Any connection with only two endpoints A dedicated data link that connects only two stations poison reverse A routing protocol command that tells its neighbor gateways that one of the gateways is no longer connected POP Point Of Presence Port An access point where data can enter or exit POTS Plain Old Telephone Service PPP over ATM Point to Point Protocol over As...

Страница 75: ...the ISO Open Systems Interconnection Reference Model routing table A table that lists routing paths to enable a node to route traffic to another node in the network RS 232 a low speed 25 position DCE DTE interface server Hardware or software that offers a specific service such as database management to a client SHDSL Symmetric High Bit Rate Digital Subscriber Loop A DSL technology that allows symm...

Страница 76: ... local and wide area networks TCP Transmission Control Protocol Telnet The TCP IP virtual terminal protocol that allows a user at one site to access a remote system at another site throughput The number of bits characters or blocks that are able to pass through a data communication system training A process where two modems try to determine the correct protocols and transmission speeds to establis...

Страница 77: ...ansmission VOD Video On Demand A service that provides video to subscribers upon request VPI Virtual Path Identifier VPI Virtual Path Identifier The 8 bit field in an ATM cell header that specifies the routing path for a cell VPN Virtual Private Network A network implemented over a public network that is made private by use of encryption VT100 A terminal used for asynchronous communications WAN Wi...

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