01. Which two statements are true about time-division multiplexing (TDM)? (Choose two.)
- TDM relies on Layer 3 protocols to operate.
- Multiple channels can transmit over a single link.
- Original data streams must be reconstructed at the destination.
- TDM methods vary depending on the Layer 2 protocol that is used.
- It allows information from multiple channels to be allocated bandwidth on multiple wires.
02. What does the demarcation point represent in data communication physical circuits?
- DTE/DCE interface on the device connecting to the Internet
- location of the firewall or router
- physical point at which the public network ends and the private customer network begins
- tag assigned to the physical block where a cross-connect occurs
- EIA/TIA 232 (RS-232)
- EIA/TIA 422 (RS-422)
- EIA/TIA 423 (RS-423)
- EIA/TIA-612/613 (HSSI)
- ITU V.35
- Parallel connections do not support error checking.
- Parallel connections are subject to excessive attenuation.
- Parallel connections are subject to clock skew and to crosstalk between wires.
- Parallel connections transmit over only two wires and therefore transmit data more slowly.
- HDLC does not support CDP.
- HDLC and PPP are compatible.
- HDLC supports PAP and CHAP authentication.
- HDLC implementation in Cisco routers is proprietary.
- HDLC is the default serial interface encapsulation on Cisco routers.
- HDLC uses frame delimiters to mark the beginnings and ends of frames.
- It is responsible for negotiating link establishment.
- It negotiates options for Layer 3 protocols running over PPP.
- It uses MD5 encryption while negotiating link establishment parameters.
- It terminates the link upon user request or the expiration of an inactivity timer.
- It can test the link to determine if link quality is sufficient to bring up the link.
- It monitors the link for congestion and dynamically adjusts the acceptable window size.
- link quality
- authentication
- dynamic flow control
- compression and network layer address for IP
- connection-oriented or connectionless communication methods
- callback
- multilink
- compression
- error detection
- to supply error detection
- to establish and terminate data links
- to provide authentication capabilities to PPP
- to manage network congestion and to allow quality testing of the link
- to allow multiple Layer 3 protocols to operate over the same physical link
- one
- two
- three
- four
- Layer 2 is down.
- LCP, IPCP, and CDPCP negotiations are in progress.
- Only the link-establishment phase completed successfully.
- Both the link-establishment and network-layer phase completed successfully.
- PAP sends passwords in clear text.
- PAP uses a 3-way handshake to establish a link.
- PAP provides protection from repeated trial-and-error attacks.
- CHAP uses a 2-way handshake to establish a link.
- CHAP uses a challenge/response that is based on the MD5 hash algorithm.
- CHAP uses repeated challenges for verification.
- MD5
- CHAP
- PAP
- NCP
- LCP is in the process of negotiating a link.
- LCP and NCP are waiting for CHAP authentication to complete.
- LCP negotiation has been successful, but NCP negotiation is in progress.
- Data is able to flow across this link.
- NCP has successfully negotiated.
- The PAP passwords did not match, so the routers are trying CHAP authentication.
- One router has suggested PAP authentication, and the other has accepted authentication but suggested CHAP authentication.
- One router can only use PAP authentication while the other router can only use CHAP, so the connection has been rejected.
- The router has agreed on IP parameters.
- The router has negotiated LCP successfully.
- The router is negotiating IP compression options.
- The router is requesting an IP address from its peer.
- The router has accepted IP but not the suggested IP options.
- It can communicate more efficiently with other Cisco devices
- It is less complex to configure
- It has less Layer 2 overhead
- It supports authentication
- The remote CSU or DSU has failed.
- The router is not sensing a CD signal.
- A timing problem has occurred on the cable.
- The line is not physically connected to the CSU/DSU.
- The router configuration contains the shutdown interface configuration command.
- Router(config)# hostname R3
R3(config)# username R1 password Cisco
R3(config)# interface Serial 0/0/0
R3(config-if)# encapsulation ppp
R3(config-if)# ip address 172.16.3.3 255.255.255.0
R3(config-if)# ppp authentication chap
- Router(config)# hostname R3 R3(config)# username R3 password Cisco R3(config)# interface Serial 0/0/0 R3(config-if)# encapsulation ppp R3(config-if)# ip address 172.16.3.3 255.255.255.0 R3(config-if)# ppp authentication chap
- Router (config)# username Router password Cisco
Router (config)# interface Serial 0/0/0
Router (config-if)# clockrate 64000
Router (config-if)# encapsulation ppp
Router (config-if)# ip address 172.16.3.1 255.255.255.0
Router config-if)# ppp authentication chap
- Router (config)# username R1 password Cisco
Router config)# interface Serial 0/0/0
Router (config-if)# clockrate 64000
Router config-if)# encapsulation ppp
Router (config-if)# ip address 172.16.3.1 255.255.255.0
Router (config-if)# ppp authentication chap
- Interface Serial0/0/0 resets very frequently.
- PPP LQM has shutdown the serial interface.
- The serial interface has no input or output queues available.
- The serial interface is not configured for a Layer 2 protocol.
- The interface has been administratively shutdown with the shutdown command.
- All username and password information that is sent will be encrypted.
- All authentication on the serial link will be accomplished using a two-way handshake.
- The Predictor algorithm will be used to compress all packets that are sent and received on the serial link.
- The serial link will be closed if the number of received packets at the destination node falls below 90 percent of the packets that are sent.
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