Chapter 3 PPPoE, GRE and BGP Flashcards
(38 cards)
What is a cable system?
- Cable systems uses a coaxial cable that carries radio frequency (RF) signals across the network.
- Cable systems provide high-speed Internet access, digital cable television, and residential telephone service.
What does DOCSIS stand for and what does it do?
DOCSIS stands for Data over Cable Service Interface Spec) is a standard that extends cable networks to carry data services.
How to enable high-seed transmissions of data
use hybrid fiber-coaxial (HFC) networks to enablehigh-speed transmission of data
what two types of equipment are required to send signals upstream and downstream on a cable system?
(CMTS) Cable Modem Termination System at the headend of the cable operator
What is DSL?
(DSL) digital Subscriber Line is a way to provide high-speed connections over installed copper wires
What is Asymmetric DSL (ADSL) ?
Asymmetric DSL (ADSL) provides higher downstream bandwidth to the user than upload bandwidth.
What is Symmetric DSL (SDSL}?
Symmetric DSL (SDSL) provides the same capacity in both directions.
DSL Connections - What is the DSL connection between?
The DSL connection is set up between the customer premises equipment (CPE) and the DSL access multiplexer (DSLAM) device located at the Central Office (CO).
What are key components in a DSL connection?
key components are:
- Transceiver or a modem in a router that connects the computer of the teleworker to the DSL
- DSLAM located at the CO of the carrier which combines individual DSL connects from the users into one high-capacity link to the ISP
What is the advantage of DSL over cable technology?
The advantage of DSL over cable technology is that DSL is not a shared medium. Each user has a separate direct connection to the DSLAM.
Wireless connections - Whatare the three main broadband wireless technologies?
- Municipal Wi-Fi -Most municipal wireless networks use a mesh of interconnected access points
- Cellular/mobile -Mobile phones use radio waves to communicate through nearby cell towers. Cellular speeds continue to increase. LTE Category 10 supports up to 450 Mb/s download and 100 Mb/s upload.
- Satellite Internet -Used in locations where land-based Internet access is not available. Primary installation requirement is for the antenna to have a clear view toward the equator.
What has WiMAX been replaced by?
WiMAX has largely been replaced by LTE for mobile access, and cable or DSL for fixed access.
What are the factors to consider selecting a broadband solution?
Cable -Bandwidth shared by many users, slow data rates during high-usage hours.
•DSL-Limited bandwidth that is distance sensitive (in relation to the ISP’s central office).
•Fiber-to-the-Home-Requires fiber installation directly to the home.
•Cellular/Mobile -Coverage is often an issue.
•Wi-Fi Mesh -Most municipalities do not have a mesh network deployed.
•Satellite-Expensive, limited capacity per subscriber
What does PPPoE do ?
PPPoE creates a PPP tunnel over an Ethernet connection.This allows PPP frames to be sent across the Ethernet cable to the ISP from the customer’s router. PPP is used to authenticate the user and assign an IP address.
PPP Configuration - what are the steps to configuring PPPoE
To create the PPP tunnel a dialer interface is configured.
•Use interface dialer number command
The PPP CHAP is then configured. Use ppp chap hostname name andppp chap password password.
The physical Ethernet interface connected to the DSL modem is enabled with the command pppoe enableinterface configuration command.
Dialer interface is linked to the Ethernet interface with the dialer pool and pppoe-clientinterface configuration
Why do you have to set the MTU to 1492?
The MTU should be set to 1492 to accommodate PPPoE headers.
What are the possible problems in PPPoE?
- Failure in the PPP negotiation process
- Failure in the PPP authentication process
- Failure to adjust the TCP maximum
What are the possible points of failure in PPPoE?
Four possible points of failure in PPP negotiation: •No response from the remote device. •Link Control Protocol (LCP) not open. •Authentication failure. •IP Control Protocol (IPCP) failure.
What is a VPN?
A VPN (Virtual Private Network) is a private network created via tunneling over a public network, usually the Internet.
What is an secure implementation of VPN with encryption?
IPsec VPN
How are VPNs implemented?
To implement VPNs, a VPN gateway is necessary -could be a router, a firewall, or a Cisco Adaptive Security Appliance (ASA).
Name some benefits for using VPNs
Cost savings -VPNs enable organizations to use cost-effective, high-bandwidth technologies, such as DSL to connect remote offices and remote users to the main site.
•Scalability-Organizations are able to add large amounts of capacity without adding significant infrastructure.
•Compatibility with broadband technology -Allow mobile workers and telecommuters to take advantage of high-speed, broadband connectivity.
•Security-VPNs can use advanced encryption and authentication protocols.
How to site to site VPNs work
Site-to-site VPNs connect entire networks to each other, for example, connecting a branch office network to a company headquarters network.
In a site-to-site VPN, end hosts send and receive normal TCP/IP traffic through a VPN “gateway”.
The VPN gateway is responsible for encapsulating and encrypting outbound traffic.
How to site to site VPNs work
Site-to-site VPNs connect entire networks to each other, for example, connecting a branch office network to a company headquarters network.
In a site-to-site VPN, end hosts send and receive normal TCP/IP traffic through a VPN “gateway”.
The VPN gateway is responsible for encapsulating and encrypting outbound traffic.
