1

Which port type should you use to connect to a two-wire analog service connecting to the PSTN for both inbound and outbound calling?

Answer:

A two-wire analog service from the PSTN is considered an FXS port. You should connect this to an FXO port in a gateway. You could connect an FXS-DID port to the PSTN, but this configuration would support outbound dialing only.

2

What types of signaling are required on a voice circuit?

Answer:

Supervisory signaling, address signaling, and informational signaling are required on a voice circuit. Supervisory signaling is used to indicated on-hook and off-hook status. Address signaling is used to convey destination information. Finally, informational signaling is used to provide user feedback, such as dial tone and ringing.

3

What is the difference between CAS and CCS on an E1 circuit?

Answer:

Although both CAS and CCS use timeslot 16 to carry signaling, CAS has specific bits within a multiframe that are dedicated, or associated to each channel. With CCS, messages are used to carry signaling information.

4

What is the difference between SF and ESF?

Answer:

An SF consists of 12 T1 frames. The framing bit is used for synchronization. Robbed-bit signaling can provide two signaling bits per channel (A and B).

An ESF consists of 24 T1 frames. In addition to synchronization, the framing bits can be used to provide data link information and CRC error correction. Robbed-bit signaling can provide 4 signaling bits per channel (A, B, C, and D).

   
5

What two types of echo are possible on a voice circuit?

Answer:

The two possible types of echo on a voice circuit are acoustic echo and hybrid echo.

Acoustic echo is caused by poor acoustic isolation between the speaker and microphone.

Hybrid echo is caused by an impedance mismatch in a 2-wire to 4-wire hybrid.

6

Which signaling type supports ANI on T1 CAS circuits?

Answer:

E&M-FGD supports reception of ANI. FGD-EANA supports transmission of ANI.

7

Which line signaling method should you use on an E1 R2 satellite link?

Answer:

You should use R2-Pulse on an E1 R2 satellite link.

8

What component of an ISDN message is used to carry information about the call?

Answer:

Call-specific information is carried in the Information Element of an ISDN message.

Part I: Voice Gateways and Gatekeepers

Gateways and Gatekeepers

Part II: Gateways

Media Gateway Control Protocol

H.323

Session Initiation Protocol

Circuit Options

Connecting to the PSTN

Connecting to PBXs

Connecting to an IP WAN

Dial Plans

Digit Manipulation

Influencing Path Selection

Configuring Class of Restrictions

SRST and MGCP Gateway Fallback

DSP Resources

Using Tcl Scripts and VoiceXML

Part III: Gatekeepers

Deploying Gatekeepers

Gatekeeper Configuration

Part IV: IP-to-IP Gateways

Cisco Multiservice IP-to-IP Gateway

Appendix A. Answers to Chapter-Ending Review Questions

Index



Cisco Voice Gateways and Gatekeepers
Cisco Voice Gateways and Gatekeepers
ISBN: 158705258X
EAN: 2147483647
Year: 2004
Pages: 218

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