Introduction to Networks & Data Comm
Cynthia Thomas/James McGuffee
3. Describe how ISPs work together to create the Internet core.
Internet Service Providers (ISPs) work together to create the internet core by creating connections to each other. First, individual ISPs create their own points of presence (POP). These POP can be geographic or global depending on the ISP. Then the ISP creates connections to their own POP creating their own TCP/IP network. Finally the individual ISPs create connections between each other’s networks. The connections between the ISPs create the internet core. Peering agreements are made between the ISPs which allows ...view middle of the document...
Once the frequencies are sent to the telco the DSLAM determines if it is voice or data based on the frequency it is receiving and forwards to a device accordingly. At the customers location the telephone wires are required to be split to create different connections for the phone and the modem. DSL uses PPP as the data link just like analog. An advantage of using DSL vs. analog is that the customer can be on the phone and on the internet at the same time.
Layer 1 & 2 using cable modem – Like DSL cable uses frequencies to differentiate between the two services being provided. Specific frequencies are used for video channels and other specific frequencies are used to data. On the customer side there is a modem and like DSL uses a DSL modem CATV uses a cable modem. Cable television (CATV) companies use a combination of coaxial cable and a hybrid fiber coaxial (HFC) cable to connect customers to its services. There are two types of connections to a customer fiber to the neighborhood (FTTN) & fiber to the curb (FTTC) fiber to the neighborhood. There is also a device there receives the frequency signal and forwards it to the internet or video devices at the service providers.
5. Compare and contrast Analog, DSL and Cable modems as Internet access technologies.
Analog requires that you cannot be on the phone at the same time as accessing the internet so the connection is not always on and downlink speeds are not faster the speeds are about 56 Kbps. DSL allows for phone calls to occur at the same time as accessing the internet and is always on. DSL does have faster downlink possibilities with an approximate speed of 24 Mbps. Cable is the same as DSL in that you can watch video at the same time as accessing the internet and therefore the connection is always on. It also allows for faster downlink possibilities with an approximate speed of 50 Mbps.
7. List the steps and actions taken at each step when a client needs to do name resolution for a hostname that exists in a different DNS subdomain.
1. A host sends a query to the DNS server it knows.
2. If that DNS knows it will return the answer, if it does not it will ask another DNS server.
3. DNS server will ask a DNS root server for help.
4. The DNS root server responds with the IP address of another DNS server.
5. The DNS server then sends a request to the DNS server IP address provided by the DNS root server.
6. A DNS server receives the request and provides the IP address for the requested subdomain to the requesting DNS server
7. The DNS server that the host originally sent the request to responds to the host with the IP address needed.
8. Compare and contrast the public IP address assignment process that was used before IP address exhaustion and after the introduction of CIDR.
Prior to the introduction of CIDR the IP address assignment was that each request received a set of network addresses. Depending on...