Internet Technology Backgrounder

Transcription

1 Summary The following information reviews the Internet and the World Wide Web This Job Aid covers: The Internet Ethernet Physical Address TCP/IP Addresses Internet Communication Internet Access Applications Internet Access during ViaSat Service Installation This Job Aid supports all audiences. The Internet The Internet is a worldwide network linking computers through a common set of TCP/IP protocols. The Internet is the transport vehicle for information. The World Wide Web is a network of servers, which allows users to access information resources using Web based tools. Computers communicating across the Internet access the information on World Wide Web servers with many different Web-based tools. Two of the most popular Web-based tools are: Internet Browsers Clients ViaSat, Inc. Page 1 of 7

2 Ethernet Physical Address Because the computer is a network device, it needs a Network Interface Card (NIC) to access a network. Like the computer, this card is supplied by the customer and generally comes with the computer. An Ethernet cable from the Satellite Modem to the computer connects the computer to the network through the NIC. The ViaSat Modem is a network device. Like a computer, it has a NIC and a MAC address. Each NIC has a unique MAC Address consisting of 6 hexadecimal numbers, separated by colons. This address is called a Physical Address because it is built into the hardware of the card. The first three numbers of the MAC Address identifies the manufacturer of the card. A ViaSat Modem MAC Address looks like this: 00:A0:BC:01:AB:48 Using the MAC Address: A technician uses the MAC address to identify the modem during the Installation and Troubleshooting processes. MAC Address Limitation: The MAC address alone is not enough for the computer to communicate with the Internet. To communicate on the Internet, the computer will need a TCP/IP Address: Internet Protocol (IP) Address ViaSat, Inc. Page 2 of 7

3 TCP/IP Addresses TCP/IP Overview Transmission Control Protocol/Internet Protocol (TCP/IP) assigns a unique address to every computer or other network device connected to the network. This address is called the Internet Protocol Address. This name is usually shortened to IP Address. An IP Address looks like this: The TCP/IP Connection: The TCPIP Connection: As seen on the graphic of a computer's network configuration page, a TCP/IP connection on a computer needs more than just an IP Address. This is true of all network devices. The components that make up the connection are: Address Type (Assignment Type) IP Address Subnet Mask Default Gateway IP Address Assignment Every network device (i.e. computer, modem, etc.) attached to the Internet needs a unique IP Address. IP Addresses can be assigned statically or dynamically. ViaSat assigns addresses in the following manner: ViaSat Consumer Accounts: Both residential and commercial use Dynamic Address Assignment. ViaSat Corporate/Government Accounts: These accounts can use either Dynamic or Static Address Assignment. Dynamic Address Assignment: A Dynamic IP Address is not stored permanently in the network device. When a computer, or other network device, is set up to use Dynamic Address Assignment, the device requests a new IP Address every time it connects to the network. The assignment setting causes the device to communicate with a Dynamic Host Configuration Protocol (DHCP) server on the network, which responds to this request and provides a unique IP address. A computer connected to the ViaSat Network may have a different IP Address every day. During service installation, the Technician makes sure that the network configuration on the customer computer is set to use DHCP. Static IP Address: A Static Address Assignment requires manual modification of a network device network configuration file. The Static IP Address is stored permanently in the device and rarely changes. This is a common assignment method for devices that need a static address to communicate with other devices on the network. The Static IP Address information resides in the networking configuration file in the device and in the DHCP server on the network. If a device requires a Static IP Address on the ViaSat network, the address will be assigned and sent to the customer after the standard ViaSat service installation is complete. The Enterprise Care team will support the Technician, if the Static IP Address computer configuration is required while the Technician is still on site ViaSat, Inc. Page 3 of 7

4 IP Address Types Private IP Addresses: Private Addresses are used in local networks. The ViaSat Network uses Private Addresses for all the modems that support the WildBlue and Exede service. This restricts the modems to inside the network and protects them from intrusion from outside the network. These addresses cannot be used across the internet and are not routable. Public IP Addresses: With the exception of Link-local and Broadcast IP address, all other IP Addresses not listed on the Private IP Range are Public IP Addresses and can be used to access the Internet. Public IP Addresses are routable and each devise uses a unique Public Address to access the Internet. IP Broadcast Addresses: Broadcast Addresses are used by the DHCP client in the computer to find and send requests to the DHCP server. These private, formulated addresses are created using the computer IP Address and the Subnet Mask. These addresses cannot be used across the internet and are not routable. Link-local Addresses: Another type of private IP Address uses the Link-local address range. While Link-local addresses can be used on limited single link connectivity, the most common use of this address is when the computer fails to find a DHCP server. So if a computer cannot obtain a network address via DHCP, an address from range is assigned. Why all these address types? For the Internet Access Control! Internet Access: Routers are used in networks to control the access to the Internet. The Router will block data using a Private IP Address and forward data using a Public IP Address.In order to simplify network administration and to conserve IP addresses, certain blocks of IP Addresses have been set aside for Private Network use ViaSat, Inc. Page 4 of 7

5 Internet Communication Two items are needed for a computer, or other network device, to communicate with the Internet: Connectivity and Data Access. Connectivity Network connectivity is necessary before actual communication can occur. Four Network Communication Configurations define network connectivity and they are as follows: Step Action 1. The MAC Address is the Physical Address of the NIC. Recall that the Technician uses the MAC Address of the Customer equipment to identify the account. In the same way, the local TCP/IP network also uses the MAC Address to identify the computer or network device. 2. The IP Address and IP Address Type define the Computer network address. This address is determined by the network; using either Dynamic or Static IP Address Assignment. 3. The Subnet Mask is a filter that defines which part of the IP Address points to the network and which part points to the computer or network device. This mask is defined by the network. 4. The Default Gateway is the Router port attached to the local network where the Computer, or network device, resides. This can be a Local Router, located at the same site as the customer equipment, or a Network Router, located within the network ViaSat, Inc. Page 5 of 7

6 Once the Network Configuration is set and connectivity is established with the network, the computer, or other network device, is ready to access the Internet. However, to access the data on the World Wide Web (WWW) an Internet Access Application is needed. For computers, this is an Internet Browser. Data Access Recall that the Internet is a worldwide network linking computers and the actual data resides on computers, called WWW Servers. For humans to view this data on a computer, it needs to be converted into a format that humans can read. Using an Internet Browser, data is translated into readable text using Hypertext Markup Language (HTML) code. The computer Internet Browser controls accessing and viewing of data; the process of viewing data on the Internet is called "browsing" or "surfing. Enhanced Browsing: Within the network, special computers called Proxy Servers are used to enhance browsing performance, filter requests, and share connections. Each Internet Service Provider will have Browser settings that work best for their network, including access to the Network Proxy Server. Each computer using the ViaSat Network will use the ViaSat Proxy Server to enhance browsing on the network. Internet Access Applications The following information provides general information about the Internet Access Application tools; the Browser and the client. Internet Browsers Browsers allow the user to view Web pages, which reside on Web servers. While the Internet provides access to the Web servers, the Browser allows the user to view the Web page information. Web programmers use Hypertext Markup Language (HTML) to write Web pages. The browser translates and interprets HTML to make the Web page viewable and understandable to the user. There are many browser software applications available to the user. The main differences between browser applications are the convenience features they offer for navigating and managing the Web pages. Mozilla Firefox, Google Chrome, and Microsoft Internet Explorer are examples of Browser software applications ViaSat, Inc. Page 6 of 7

7 Client An Client resides on the computer and enables the user to create, read, and organize messages. Based on client-server architecture, it requires a specific server residing on the Internet to complete its tasks. Most client applications use the Simple Mail Transfer Protocol (SMTP) protocol to request the server to send . Examples of client applications: Outlook (Windows) Apple Mail (Mac) Thunderbird (Windows, Mac) Internet Access during ViaSat Service Installation Exede/SurfBeam 2 IP Addressing: Point and Peak: During the PnP process the Computer is only connected to the Modem. The Link- Local IP Address the Computer uses is supplied by the modem. This is local to the connection between the Modem and the Computer. The purpose of this connection is for the user to access Modem Browser Interface (MBI). Modem Lock: During Modem Lock the modem gets its IP Address from the network, allowing the computer to request a new IP Address from the network. Computer Connectivity: After successful Modem Lock, the attached Computer no longer has an IP Address, so it must make a DHCP request again. This request goes through the modem and the network links to the Network DHCP server. o For SurfBeam 2 / Exede service, this will be a Public IP address Provisioning: The Computer is provided a Public IP Address by the DHCP server before the Provisioning process begins. Because the IP Address request came from an un-provisioned Modem, the IP Addressed is tagged to be routed to the Walled Garden to start Provisioning. WildBlue SurfBeam IP Addressing: Point and Peak: During the PnP process the Computer is not connected to the Modem and no IP Addressing is used. Unlike the SB2 Modem, the SB Modem PnP process is guided by external hardware tools; the APA and the Satellite Signal Level Meter. The computer is not connected to the Modem until after the Modem Lock process is complete. Modem Lock: The Modem Lock process allows the modem to get an IP Address from the network. The computer is not connected in this process. Computer Connectivity: After successful Modem Lock, the Computer is connected to the Modem for the first time and booted up. It has no IP Address, so it must make an IP Address request. This request goes through the modem and the network links to the Network DHCP server. o For SurfBeam / WildBlue service, this will be a Private IP address. Provisioning: During Provisioning the network knows that the computer IP Address is Private. The network router sends the request through the ViaSat Network to Conexon Provisioning ViaSat, Inc. Page 7 of 7