However, the proxy agent cannot be run on a computer that is also a WINS server.
`Consult with the network administrator to determine whether your computer
`should be
`
`configured as a WINS proxy agent, as enlyoniy a few computers on each
`subnetwork should
`
`be configured for this feature.
`ll. When.you are done setting advanced options, choose the OK button. When
`the TCP/IP
`Configuration dialog box reappears, choose the OK button. When the Network
`Settings
`dialog box reappears, choose the OK button to complete advanced TCP/IP
`configuration.
`You must restart the computer for the changes to take effect.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`..
`
`.
`
`..
`
`.
`
`..
`
`.
`
`l
`
`~— — —— —— — — ~ ~ — — — — ~ — — — ~~ "7."* — — — — — ~ —— —,;*..*
`J9n¢¢ wan:m1=mr..
`l~ “:a mmw_
`IIWM w~¢:#\wrWmu~::~l: wS#:
`lIlIlIlIlIlIlI__l|lI::lI ___
`fiend Trap with Community Hamas
`Egmmunity Names
`lrap Destination fm engineering
`IP Hnstfhddleee or
`
`MP1—"El1'& fpyq hddress
`Installing and Configuring Microsoft TCP/IP and SNMP 9 ofl3
`Configuring SNMP
`The SNMP service is installed when you check the SNMP Service option in the
`Windows NTTGP+IP§;
`TCP[lP Installation Options dialog box. After the SNMP service software is
`installed on your
`computer, you must configure it with valid information for SNMP to operate.
`You must be logged on as a member of the Administrators group for the local
`computer to
`configure SNMP.
`The SNMP configuration information identifies communities and trap
`destinations.
`
`l A
`
`eemmenityA Community is a group of hosts to which a Windows NTeemputergg
`computer running the SNMP
`service belongs. You can specify one or more communities to which the Windows
`NTeemputerNT
`computer using SNMP will send traps. The community name is placed in the SNMP
`packet
`when the trap is sent.
`When_the SNMP service receives a request for information that does not contain
`the
`
`correct community name and does not match an accepted host name for the
`service,
`the
`SNMP service can.send.aerapa trap to the trap destination(s), indicating that
`the request failed
`authentication.
`
`I; Trap destinations are the names or IP addresses of hosts to which you want
`the SNMP
`
`service to send traps with the selected community nameri
`You.might want to use SNMP for statistics, but may not care about identifying
`communities or
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 31
`
`

`
`In this case, you can specify the "public" community name when you
`traps.
`configure the
`SNMP service.
`
`.,.. To configure the SNMP service
`1 .
`Start the Network option in Control Panel to display the Network Settings
`dialog box. Enig the
`Installed Network Software list box, select SNMP Service, and choose the
`Configure
`button. The SNMP Service Configuration dialog box appears.
`SNMP—Serviee—Genf&guratmn
`
`2T—;:TO identify each community to which you want this computer to send.traps,
`type the name
`in the Community Names box. After typing each name, choose the Add button to
`move the
`
`name to the Send Traps With Community Names list on the left.
`Typically, all hosts belong to public, which is the standard name for the
`common
`
`community of all hosts. To delete an entry in the list, select it and choose
`the Remove
`button.
`Note
`
`Community names are case sensitive.
`3e——é=To specify hosts for each community you send traps to, after you have
`added the
`
`community and while it is still highlighted,
`Host/Address Or
`IPX
`
`type the hosts in the lP;§
`
`Address box. Then choose the Add button to move the host name or-lP;§ address
`to the
`
`Trap Destination for the seleetedsegecfed community list on the left.
`You can enter a host nameT£ its lP;§ addressTé or its lPX;§§ address.
`To delete an entry in the list, select it and choose the Remove button.
`“
`
`é=To enable additional security for the SNMP service, choose the Security
`button. Continue
`
`with the configuration procedure, as described in the next section,
`"Configuring SNMP
`Security."
`
`5.?
`
`£=TO specify Agent
`services), choose
`
`information (comments about the user,
`
`location, and
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 32
`
`

`
`the Agent button. Continue with the configuration procedure, as described.in
`"Configuring
`SNMP Agent Information" later in this chapter.
`
`6w————
`
`ézwhen you have completed.allg;; procedures, choose the OK button. When the
`Network
`
`Settings dialog box reappears, choose the OK button.
`The Microsoft SNMP service has been configured and is ready to start. lt is
`not necessary
`to reboot the computer.
`
`8 Send fxglhentiealion Trap
`—heeepted Community jiames
`Cobrglmunity Name
`'0 Ageept SNMP Packete from Any Host
`—Lil"
`.Qnly .¢|.¢;:c:&pt SHHP Packets fmm These Hosts:
`[F Hestfhddress or
`IPX Address:
`ublic
`
`=JiL1 li " mm— g
`11.101.41.121
`
`Installing and Configuring Microsoft TCP/IP and SNMP lO<>f13
`Configuring SNMP
`Configuring SNMP Security
`SNMP security allows you to specify the communities and hosts aeemputerg
`computer will accept
`requests from, and to specify whether to send an authentication.trap when an
`unauthorized
`
`community or host requests information.
`11JJ>
`
`To configure SNMP security
`1.
`Start the Network option.in.Control Panel to-displaydispiay the Network
`Settings dialog box.
`In the
`Installed Network Software list box, select SNMP Service and choose the
`Configure button:
`2.
`In the SNMP Service Configuration dialog box, choose the Security
`button.
`
`
`
`If you want to send a trap for failed.authentications, select the Send
`3.
`AeEhenEieatienAutnentication Trap
`check box in the SNMP Security Configuration dialog box.
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 33
`
`

`
`E]
`
`;
`
`H.
`
`3;
`
`E.
`
`.
`
`.
`
`E
`
`2
`
`3E
`
`type the community names you will accept
`
`In the Community Name box,
`4.
`requests fromT
`Choose the Add button aelerafter typing each name to move the name to the
`Accepted
`Community Names list on the left.
`AhestA host must belong to a community that appears on this list for the SNMP
`service to accept
`requests from that host. Typically, all hosts belong to public, which is the
`standard name
`
`for the common community of all hosts. To delete an entryently in the list,
`select it and choose
`the Remove button.
`
`{in
`
`é=Select an option to specify whether to accept SNMP packets from any host
`or from only
`specified hosts.
`I;:If the Accept SNMP Packets Fron1Any Host option is selected, no SNMP packets
`are
`
`rejected on the basis of source host ID. The list of hosts under Only Accept
`SNMP
`Packets From These Hosts has no effect.
`
`l I
`
`f‘ lf the Only Accept SNMP Packets From These Hosts option is selected, SNMP
`packets will be accepted only from the hosts listed. In the lP;§ Host/Address
`Or
`IPX
`
`Address box, type the host names, lP;§aaddresses, or IPX addresses of the hosts
`from
`
`which you will accept requests. Then choose the Add button to move the host
`name or
`
`IP address to the list box on the left. To delete an entry in the list, select
`it and choose
`the Remove button.
`gr
`
`é=Choose the OK button. The SNMP Service Configuration.dialog box reappears.
`To specify Agent information (comments about the user,
`location, and
`services), choose
`the Agent button. Continue with the configuration procedure, as described in
`the next
`section.
`
`4w————
`
`é=After you complete all procedures, choose the OK button. When the Network
`Settings
`dialog box reappears, choose the OK button.
`The Microsoft SNMP service and SNMP security have been configured and are ready
`to
`
`start. You do not need to reboot the computer.
`
`—nn—n—4
`
`Qnntact:
`Location:
`
`l
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 34
`
`

`
`Ehysical Qatalink .»" Subnetwork
`internet >< ind—tu—End
`
`><:
`
`igpplicatiorzsi
`.H.
`
`Ernest Ayde 0He
`Bldg. T, mum 823
`Installing and Configuring Microsoft TCP/IP and SNMP ll ofl3
`Configuring SNNIP
`Configuring SNMP Agent Information
`SNMP agent infennatieninformation allows you to specify comments about the
`user and the physical
`location.of the computer and to indicate the types of service to report. The
`types of service that
`can be reported are based on the computer's configuration.
`:TT———To configure SNMP agent
`information
`%l:.Start the Network option in Control Panel to display the Network Settings
`dialog box. Isl; the
`Installed Network Software list box, select SNMP Service and choose the
`Configure button.
`2.
`In_the SNMP Service Configuration.dialog box, choose the Agent button.
`
`D1theSNMPAgentdialogbox,typethecomputeruser'snameiJ1theContact
`3.
`box and the
`
`computer's physical location.in;g the Location.box. These are comments that
`will be used as
`text and cannot
`
`include embedded control characters.
`
`Select the services to report in the Service box. Check all boxes that
`4.
`indicate network
`
`capabilities provided by your Windows NT computer. SNMP must havenave this
`iafeaaatieninformation to
`
`manage the enabled services.
`If you have installed additional TCP/IP services, such.as a bridge or router,
`you should
`consult RFC 1213 for additional infennatieninformation.
`
`Option
`Physical
`
`Meaning
`Select this option if this Windows NT computer manages any
`
`physical TCP+4IP device, such as a repeater.
`Datalink/subnetwork
`Select this option.if this Windows NT'computer manages
`a TCP-!-4IP
`subnetwork or dasalinkdataiink, such as a bridge.
`Ghapter—2—InsEall&ng—aHd—GeHfigHriHg—Miereseft—TGPnP—aad—SNMP
`E
`.
`.
`
`Internet Select this option if this Windows NT computer acts as an lP;=
`gateway.
`
`End—to—End Select this option if this Windows NT computer acts as an lP;=
`host.
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 35
`
`

`
`This option should be selected for all Windows NT installations.
`
`
`5T£ Choose the OK button.
`6T——é:When the SNMP Service Configuration dialog box reappears, choose the
`OK button.
`
`When the Network Settings dialog box reappears, choose the OK button.
`SNMP is now ready to operate without rebooting the computer.
`Applications Select this option if this Windows NT computer includes any
`applications that use TCP/IP, such as electronic mail. This option
`should be selected for all Windows NT installations.
`
`Installing and Configuring Microsoft TCP/IP and SNMP 12 ofl3
`Removing TCP/IP Components
`If you want to remove the TCP/IP protocols or any of the services installed
`on a computer, use
`the Network option in Control Panel to remove it.
`When you remove any network software, Windows NT warns you that the action
`permanently
`removes that component. You cannot reinstall aeempenenea component that has
`been removed until after
`
`you restart the computer.
`ww7w——To remove any TCP/IP component
`lT——;é=In Control Panel, choose the Network option.
`2.
`In the Installed Network Software list in the Network Settings dialog
`box, select the
`component that you want to remove.
`3.
`Choose the Remove button.
`
`Installing and Configuring Microsoft TCP/IP and SNMP laOfl3
`Configuring RAS for Use with TCP/IP
`Windows NT‘users who install Remote.Access Service (RAS) for remote networking
`maintain
`
`all the benefits of TCP/IP;§ networking,
`capabilities of
`Microsoft TCP/IP. RAS clients can be configured to use Point to Point Protocol
`(PPP) or Serial
`
`including access to the WINS and.DNS
`
`Line Internet Protocol (SLIPSLlP) tc>allow'TCP/IP(iial—up support for existing
`TCP/IP;§ internetworks
`and.the-Inteaaaeeinternet. When PPP is configured.on.aiNindows NT'Remote.Access
`server, it can
`function as a router for RAS clients. SLIPSLIP client software is provided
`to support older
`implementations+£ it does not support multiple protocols.
`As with all network services, you install RAS by using the Network option in
`Control Panel.
`
`During RAS installation and configuration, you can specify the network
`protocol settings to use
`for RAS connections, which also allows you to specify TCP/IP configuration
`settings. When the
`network administrator installs a Microsoft RAS server,
`reserved for use by
`
`IP addresses are
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 36
`
`

`
`RAS clients.
`
`Users with RAS client computers can use the Remote Access program to enter
`and maintain
`
`names and telephone numbers of remote networks. RAS clients can connect to
`and
`
`disconnect fronithese networks through the Remote.Access progranu You can also
`use the
`
`Remote Access Phone Book application to select the network protocols to use
`for aspeeifie—a specific
`Phone Book entry. lfTGP+If TCP[IP is installed, the Phone Book automatically
`selects TCP+;IP over
`PPP as the protocol.
`If a RAS client computer has a serial COM port, you can use the Remote Access
`Phone Book
`
`application to configure SLIP for use with aseleeteda selected Phone Book
`entry. If you configure a RAS
`client computer to use the SLIP option, when you dial in for aeenneetieng
`connection to the selected Phone
`
`the Terminal screen appears, and you can begin an interactive
`Book entry,
`session with aSLIP—a SLIP
`
`server. When you use SLIP, Remote Access Phone Book bypasses user
`authentication. You
`
`will not be asked for a usemameusername and password.
`For complete information about setting up RAS servers and clients and using
`RAS with
`
`Windows NT, see Windewsvwgvdows NT Serversenger Remote Access Service.
`€HAP¥ER—3
`
`Networking Concepts for TCP/IP
`¢This chapter describes how'TCP/IP fits in the Windows NT‘network architecture
`and explains
`the various components of the Internetinternet Protocol suite and IP
`addressing. As part of the
`discussion on name resolution in Windows networking,
`describes NetBIOS
`
`this chapter also
`
`over TCP/IP and Domain Name System (DNS). For additional information about
`these topics,
`see the books listed in ¢¢;Finding More Infermatienlnformation" in
`"WelcomeT;"
`¢This chapter alsc>provides conceptual information.about-ewetvvo key features
`for Microsoft TCP/IP:
`Dynamic Host Configuration.Protocol
`(WINS).
`
`(DHCP) and.Windows Internet Name Service
`
`¢The fellewingfoiiowing topics appear in this chapter:
`
`4; TCP/IP and Windows NT networking
`4; Internet protocol suite
`4; IP addressing
`4; Name resolution for Windows networking
`4; SNMP
`
`E
`
`,
`
`3
`
`.
`
`3
`
`Chapter 3
`
`lof17
`
`1.
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 37
`
`

`
`SIIIUP RPC
`Windows So—ckas
`
`Applications
`Wiruziosna Sockets
`Interface
`Windows
`
`HdB103 .Fhpplications
`Haslos Intaface
`naslos wer TCPJIP
`
`2 N
`
`DIS Ul‘i\_|El'S sun PPP
`IQELLE
`
`The architecture of the Microsoft Windows NT operating systen1with.integrated
`networking is
`protocol—independent. This architecture,
`figure, provides
`Windows NT file, print, and other services over any network protocol that uses
`exports from
`the TDI interface. The protocols package network requests for applications
`in their respective
`formats and send the requests to the appropriate network adapter via the
`aeewerknefwork device
`
`illustrated in the following
`
`interface Tkpeeefeeatieaspecification (NDIS)
`specification allows multiple network
`protocols to reside over a wide variety of network adapters and media types.
`.
`3
`.
`3
`E
`1
`:9
`J.
`.
`J.
`.
`Windews—SeekeesNeEBIGS—Ifi%erfaee—Ifiterfaee
`Transnort Deviw..
`lmterface
`Stardard
`
`interface. The NDIS
`
`Tcpnp
`Mcdules
`NeEwerkMetxmork Driver
`
`Interlaee
`Interface
`
`Physieal—NetwerkPhyafcel Tdatxmcrk Layer
`Architectural Model of Windows NT with TCP/IP
`
`Under the Windows NT transport—independent architecture, TCP/IP;§ is a
`protocol family that can
`be used.to offer Windows networking capabilities. The TCP/IP;§:protocol gives
`Windows NT,
`Windows for Workgroups, and.LAN Manager computers transparent access to each
`other and
`
`allows communication.with.non—;Microsoft systems in the enterprise network.
`€hap%er—3—Networking Concepts for T€PaPTCP[IP
`In%ernee—Pre%eeel—Sai%e
`
`and Windows NT Networking
`2ofl7
`
`TCP/IP refers to the Internet suite of protocols. It includes a set of
`standards that specify how
`computers communicate and gives conventions for connecting networks and
`routing traffic
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 38
`
`

`
`through the connections.
`The Internet protocols are a result of a Defense Advanced Research Projects
`Agency
`(DARPA) research project on network interconnection in the late l94Gl970s.le
`;; was mandated on all
`United States defense long—haul networks in 1983 bat—wasbutwas not widely
`accepted until it was
`integrated.with.4.2 Berkeley Software Distribution.(BSD) UNIX. The popularity
`efT€Pof TCP/IP is
`based on: I
`
`Robust client—server framework. TCP/IP;§ is an excellent client—server
`application platform,
`especially in wide—area network (WAN) environments.
`9:.-
`
`Implementations efTGPof TCP/IP are available on
`
`Infermatienl information sharing. Thousands of academic, military,
`scientific, and commercial
`organizations sharesnare data, electronic mail, and.services on the Internet
`using TCP/IP.
`I; General availability.
`nearly every popular
`computer operating system. Source code is widely available for many
`implementations.
`Vendors for bridges, routers, and.network analyzers all offer support for the
`TCP/IP
`protocol suite within their products.
`The following discussion introduces the components of the —I—P£ protocol suite.
`Some knowledge
`of the architecture and interaction between TCP/IP components is useful for
`both
`
`administrators and users, but most of the details discussed here are
`transparent when you are
`actually using TCP/IP.
`Networking Concepts for TCP/IP
`Internet Protocol Suite
`3of17
`
`Internet Protocol Suite
`Transmission Control Protocol and Internet Protocol
`
`Transmission Control Protocol
`members of the IP
`
`(TCP) and Internet Protocol
`
`(IP) are only two
`
`protocol suite. IP is a protocol that provides packet delivery for all other
`protocols within the
`TCP/IP family. IP provides a best—effort, connectionless delivery system for
`computer data.
`That is,
`IP packets are not guaranteed to arrive at their destination, nor
`are they guaranteed to
`be received in the sequence in which they were sent. The protocol's checksum
`feature
`
`confirms only the IP header's integrity. Thus, responsibility for the data
`contained within the IP
`
`packet (and the sequencing) is assured only by using higher— level protocols.
`Perhaps the most common.higher—IeveliPlevel IP protocol is TCP. TCP supplies
`a reliable,
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 39
`
`

`
`connection—based protocol over (or encapsulated within)
`the delivery of
`packets, ensures proper sequencing of the data, and provides aeheeksumg
`checksum feature that
`
`IP. TCP guarantees
`
`validates both the packet header and its data for accuracy. Inig the event
`that the network either
`
`corrupts or loses aTGPa'TCP/IP packet during transmission, TCP is responsible
`for retransmitting
`the faulty packet. This reliability makes TCP/IP the protocol of choice for
`session—based data
`
`transmission, client—server applications, and critical services such as
`electronic mail.
`
`This reliability has a price. TCP headers require the use of additional bits
`to provide proper
`sequencing of information, as well as a mandatory checksum to ensure
`reliability of both the
`TCP header and the packet data. To guarantee successful data delivery,
`protocol also
`requires the recipient to acknowledge successful receipt of data.
`Such acknowledgments (or AGK7sACKS) generate additional network traffic,
`diminishing the level of
`data throughput in.favor of reliability. To reduce the impact on.performance,
`most hosts send
`
`the
`
`an acknowledgment for every other segment or when an ACK timeout expires.
`Networking Concepts for TCP/IP 4of17
`
`Internet Protocol Suite
`
`User Datagram Protocol
`
`Ifif reliability is not essential, User Datagram Protocol
`complement, offers a
`connectionless datagraniservice that guarantees neither delivery nor correct
`sequencing of
`delivered packets (much like lP;§). Higher—level protocols or applications
`may provide reliability
`mechanisms in addition.to UDP/IP. UDP data checksums are optional, providing
`a way to
`exchange data over highly reliable networks without unnecessarily consuming
`network
`
`(UDP), aTGPa TCP
`
`resources or processing time. When UDP checksums are used, they validate both
`header and
`
`data. AGKsACKS are also not enforced by the UDP protocol+£ this is left to
`higher—level protocols.
`UDP also offers one—to—many service capabilities, because it can be either
`broadcast or
`multicast.
`
`Networking Concepts for TCP/IP 50f17
`
`Internet Protocol Suite
`
`Address Resolution Protocol and Internet Control Message
`Protocol
`
`Two other protocols in the IP suite perform important functions, although
`these are not directly
`related to the transport of data: Address Resolution Protocol
`Iateraeeinternet Control
`
`(ARP) and
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 40
`
`

`
`(ICMP). ARP and lGMPICMP are maintenance protocols that
`
`Message Protocol
`support the lP;§
`framework and are usually invisible to users and applications.
`IP packets contain both source and.destination.IP addresses, but the hardware
`address of the
`
`destination computer system must also be known.
`hardware address by
`broadcasting a special inquiry packet
`containing the IP address of the
`system with which it is attempting to communicate. AllAli of the ARP—enabled
`nodes on the local
`
`(an ARP reqees£—paeketrequesfpackef)
`
`IP acquires a system's
`
`IP network detect these broadcasts, and.the system that owns the lP;§ address
`in question
`replies by sending its hardware address to the requesting computer system in
`an ARP reply
`packet. The hardware/IP address mapping is then stored in the requesting
`system's ARP
`cache for subsequent use. Because the ARP reply can also be broadcast to the
`network, it is
`likely that other nodes on the network can use this information.to1xpdate their
`own ARP
`
`(You can use the arp utility to view the ARP tables.)
`caches.
`€hapter—%—Netwerking—€eneepts—fer—T€PnP
`ICMP allows two nodes on an IP network to share IP status and error information.
`This
`
`information can be used by higher—level protocols to recover from transmission
`problems or by
`network administrators to detect network trouble. Although ICMP packets are
`encapsulated
`within IP packets, they are not considered to be a higher—;level protocol (ICMP
`is required in
`every TCP/IP implementation). The ping utility makes use of the ICMP echo
`reqeestrequesf and echo
`reply packets to determine whether a particular IP node (computer system) on
`a network is
`
`functional. This is useful for diagnosing IP network or gateway failures.
`Networking Concepts for TCP/IP 6of17
`
`£P—Addressing
`Ahes%A.host is any device attached to the network that uses TCP/IP. To receive
`and deliver packets sueeessfully
`successfuily between hosts, TCP/IP reliesreiies on three pieces of
`information that the user
`
`IP address, subnet mask, and default gateway.
`provides:
`The network administrator provides each of these pieces of information for
`configuring TCP/IP
`on a computer. Windows NT users on networks with DHCP servers can take
`advantage of
`automatic system eentiguratienconfiguration and do not need to manually
`configure TCP/IP parameters.
`This section provides details about IP addresses, subnet masks, and IP
`gateways.
`Networking Concepts for TCP/IP
`IP Addressing
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 41
`
`

`
`70fl7
`
`IP Addressing
`IP Addresses
`
`Every host interface, or node, on aTGPa TCP/IP network is identified by a
`unique IP address. This
`address is used to identify a host on a network+£ it also specifies routing
`information in an
`
`internetwork. The IP address identifies aeemputera computer as a 32-bit
`address that is unique across a
`TCP/IP network. An.address is usually represented.in.dotted.decimal notation,
`which depicts
`each octet (eight bits, or one byte) of an-IP;§ address as its decimal value
`and separates each
`octet with a period. An IP address looks like this:
`102.54.94.97
`
`Important
`Because IP addresses identify nodes on an interconnected.network, each host
`on the
`
`internetwork must be assigned.a unique IP address, valid for its particular
`network.
`Network ID and Host
`
`ID
`
`Although an lP;§ address is a single value, it contains two pieces of
`information:
`the network lD;2
`and theggg host
`(or system)
`IBLQ for your computer.
`l;'The netwerk—lDnefwork ID identifies a group of computers and other devices
`that are all located on
`
`the same logical network, which are separated or interconnected.by routers.
`In
`
`internetworks (networks formed by aeelleetiena collection of local area
`networks),
`there is a unique
`network IBLQ for each network.
`I; The hest—IDhosf [D identifies your computer within a particular network
`lB;2.
`(A host is any device
`that is attached to the network and uses TCP/IP.)
`Networks that connect to the public Internet must obtain an official network
`lB;2 from the
`lnterNIC to guarantee lP;§ network-IBLQ uniqueness. The lneerNIGInterNlC can
`be contacted via electronic
`
`mail at info@internic.net (for the United.States, l—8GG——444—4%4518004444345
`or,
`for Canada and overseas, 6&9—455—46GG
`6I94554600). Internet registration requests can be sent to
`hostmaster@internic.net. You can
`
`also use FTP to connect to is.internic.net,
`change to the
`/INFeSeURGElNFosouRcE/FAQ directory.
`After receiving a network IBID,
`the local network administrator must assign
`unique host
`IDs for
`computers within.the local network. Although.private networks not connected
`to the Internet
`
`then log in as anonymous, and
`
`can.choose to use their own.network identifier, obtaining"a'valid.network-ID;Q
`from IflterNI€lnterNlC
`
`allows a private network to connect to the Ifiternetinternet in the future
`without reassigning addresses.
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 42
`
`

`
`The Internet community has defined address classes to accommodate networks
`of varying
`sizes. Each network class can be discerned from the first octet of its 19;:
`address. The following
`table summarizes the relationship between.the first octet of a given address
`and its network 4B;2
`and host ID fields. Isl; also identifies the total number of network IDs and
`host IDs for each
`
`address class that participates in the Internet addressing scheme. This sample
`uses w.x.y.z to
`
`designate the bytes of the 4P;§ address.
`€hapter—3—Netwerking—€eneepts—fer—T€PnP
`IP Address Classes
`Avai4ab4e——Avai4ab4e
`
`Networking Concepts for TCP/IP 8of17
`Classafi&Hes4T2—Netwerkflwvalues1,2NetworkZH)HostID AvailableAvailable
`networks hosts per
`net
`
`A 1126 W X.y.z
`
`126 16.777214
`
`16,384 —657534—65.534
`B —128—49&——wTx——128191 W.X y.z
`
`e——44J2—22%—C 192223 w.X.y
`z —27994745&—2 097 1 51 254
`I; Inclusive range for the first octet in the IP address.
`2 The +}ddressaddress 127 is reserved for loopback testing and interprocess
`communication on the local eumputer+computer, it is not a valid network
`address.
`
`Addresses 224 and above are reserved for special protocols (IGMP
`multicast and others), and cannot be used as host addresses.
`AneewerkA network host uses the network ID and host
`ID to determine which
`
`packets it should receive
`or ignore and to determine the scope of its transmissions (only nodes with
`the same network ieig
`accept each other's 4P;§—level broadcasts).
`Because the sender's 1P;§ address is included.in.every outgoing-lP;§ packet,
`it is useful for the
`
`receiving computer system to derive the originating network ID and host ID
`from the 4P;§ address
`field. This is done by using subnet masks, as described in the following
`section.
`Subnet Masks
`
`Subnet masks are 32-bit values that allow the recipient of 1P packets to
`distinguish the network
`ID portion of the 1P address from theggg host ID. Like an lP;§ address,
`value of asubneta subnet mask is
`
`the
`
`frequently represented in dotted decimal notation. subnet masks are
`determined by assigning
`1's to bits that belong to the network iegg and 0's to the bits that belong
`to the host
`ID. Once the
`
`bits are in place, the 32-bit value is converted to dotted decimal notationTé
`as shown in the
`
`following table.
`
`
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 43
`
`

`
`llllllli—éi&&&&&&&&&&&&&&—9€999€99—255w%55¢255TG
`
`The result allows TCP/IP to determine the host and.network-IDs;2§ of the local
`computer. For
`
`example, whenwnen the lP;§ address is 102.54.94.97 and the subnet mask is
`
`%557%55w97G7255.255.O.O the
`network ID is 102.54 and the host ID is 94.97.
`
`Although configuring a host with asubneta subnet mask might seem redundant
`after examining the
`previous tables (since the class of a host is easily determined), subnet masks
`are also used to
`
`further segment an assigned network &0;2 among several local networks.
`For example, suppose a network is assigned the Class—8§ network address
`144.100. This is
`
`one of over 16,000 Class—%§ addresses capable of serving more than 65,000
`nodes. However,
`the worldwide corporate network to which this ID is assigned is composed of
`12 international
`
`LANs with 75 to $00120 nodes each. Insteadinstead of applying for 11 more
`network IDs, it is better to
`use subnetting toinakeinore effective use of the assigned ID 144.100. The third
`octet of the IP
`
`address can be used as a subnet ID,
`This splits the
`Class—%§ address into 254 subnets: 144.100.1 through 144.100.254, each of
`which can have
`
`to define the subnet mask 255.255.255.0.
`
`254 nodes.
`are used as
`
`(Host IBsg;;=0 and.255 should.not be assigned to a computerri they
`
`broadcast addresses, which are typically recognized by all computers.) Any
`12 of these
`
`network addresses could be assigned to the internationalljmflsiJ1this example.
`Within each
`
`LAN, each computer is assigned.aeniquea.unigue host ID, and.they all have the
`subnet mask
`255.255.255.0.
`
`The preceding example demonstrates a simple (and common) subnet scheme for
`Class—Baddresses§
`addresses. Sometimes it is necessary to segment only portions of an octet,
`using only a few
`Address
`class
`Bits for subnet mask subnet
`mask
`Class A 11111111 00000000 00000000
`00000000
`255.0.0.0
`Class B llllllll llllllll 00000000
`00000000
`255.255.0.0
`Class C llllllll llllllll llllllll
`OOOOOOOO
`255.255.255.0
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 44
`
`

`
`bits to specify subnet IDs;Q§ (such as when subnets exceed 256 nodes). Each
`user should check
`
`with the local network administrator to determine the network's subnet policy
`and the correct
`
`subnet mask. For all systems on the local network,
`the same for that
`network ID.
`
`the subnet mask must be
`
`Important
`All computers on.a logical network must use the same subnet mask and network
`ID+£ otherwise,
`addressing and routing problems can occur.
`
`IP Addressing
`Routing and IP Gateways
`TCP/IP networks are connected by gateways (or routers), which have knowledge
`of the
`
`networks connected in the internetwork. Although each IP host can maintain
`static routes for
`
`specific destinations, usually the default gateway is used to find remote
`destinations.
`(The
`
`default gateway is needed only for computers that are part of an internetwork .)
`Ghapter—3—Netwerking—Geaeepts—fer—T€PaP
`When.lP;§ prepares to send a packet, it inserts the local (source) IP address
`and the destination
`
`address of the packet in the lP;§ header and checks whether the network ID
`of the destination
`
`matches the network ID of the source. If they match,
`directly to the
`destination computer on the local network. Ifthelf the network IDs do not
`match,
`the routing table is
`examined for static routesvi If none are found,
`the default gateway for
`delivery.
`The default gateway is aeemputera computer connected to the local subnet and
`other networks that has
`
`the packet is forwarded to
`
`the packet isig sent
`
`knowledge of the network IDs for other networks in the internetwork and how
`to reach them.
`
`Because the default gateway knows the network IDs of the other networks in
`the internetwork,
`it can forward the packet to other gateways until the packet is eventually
`delivered to a gateway
`connected to the specified destination. This process is known as routing.
`N!jI0[E§
`Network
`
`A *
`
`§ Network
`Dther
`C
`networks
`
`Internetwerklnternetwork Routing Through Gateways
`On networks that are not part of an internetwork, IP gateways are not required.
`If a network is
`
`part of an internetwork and a system does not specify a default gateway
`(or iftheif the gateway
`
`Petitioner Sipnet EU S.R.O. - Exhibit 1018 - Page 45
`
`

`
`computer is not operating properly), only communication beyond the local
`subnet is impaired.
`Users can.add static routes by using the route utility to specify a route for
`apartiealara particular system.
`Static routes always override the use of default gateways.
`If the default gateway becomes unavailable,
`the computer cannot communicate
`outside its own
`
`subnet. Multiple default gateways can be assigned to prevent such a problem.
`When aeemputerg
`computer is configured with multiple default gateways, retransmission
`problems result in the
`system trying the other routers in the configuration to ensure
`intemetwerkinginternetworking communications
`capabilities. To configure multiple default gateways in.Windows NT, you must
`provide an lP;§
`address for each gateway in the Advanced Microsoft TCP/IP Configuration dialog
`box, as
`
`described in Chapter 2, "Installing and Configuring Microsoft TCP/IP and
`SNMP."
`
`Networking Concepts for TCP/IP 9of17
`IP