CICD - Definitions

Question 1

VoIP

Answer 1

Transmission of voice Signaling protocols and voice media over an IP network

Question 2

Nyquist Theorem

Answer 2

When sampling an analog waveform, the sampling rate must be at least twice the highest frequency being sampled

Question 3

Quantization Noise

Answer 3

Audible noise resulting from imprecise measurements when sampling

Question 4

CODEC (Coder-Decoder)

Answer 4

An algorithm that can encode an analog waveform as digital information and than decode the digital information back to analog waveform

Question 5

Call Agent

Answer 5

Is a device (Ex: server, router) that controls call setup and teardown, in addition to many other call processing tasks, such as digit manipulation

Question 6

AUDIO REQUIEREMENTS

Answer 6

Jitter must be less than 30ms
Delay must be less than 150ms ONE-WAY
Loss must be less than 1%
QoS model is DSCP EF
Bandwidth usage is Little

Question 7

VIDEO REQUIEREMENTS

Answer 7

Jitter must be less than 30ms
Delay must be less than 150ms ONE-WAY
Loss must be less than 1%
QoS model is DSCP AF41
Bandwidth usage is LOTS

Question 8

Integrated Service - QoS INTSERV

Answer 8

IntServ uses Resource Reservation Protocol (RSVP) to explicitly signal the QoS needs of an application’s traffic along the devices in the end-to-end path through the network. If every network device along the path can reserve the necessary bandwidth, the originating application can begin transmitting.

Question 9

Differenciated Service - QoS DIFFSERV

Answer 9

The DiffServ architecture model (RFC 2475, December 1998) divides traffic into a small number of classes, and allocates resources on a per-class basis. Because DiffServ has only a few classes of traffic, a packet’s “class” can be marked directly in the packet. In the DiffServ model, packets are classified and marked to receive a particular forwarding treatment (per-hop behavior or PHB) on nodes along their path.

Question 10

Fragmenting and Interleaving IP Traffic

Answer 10

Interactive traffic (Telnet, Voice over IP, and the like) is susceptible to increased latency and jitter when the network processes large packets (for example, LAN-to-LAN FTP transfers traversing a WAN link), especially as they are queued on slower links. The Cisco IOS LFI feature reduces delay and jitter on slower-speed links by breaking up large datagrams and interleaving low-delay traffic packets with the resulting smaller packets

Question 11

Weighted Random Early Detection

Answer 11

Random Early Detection (RED) is a congestion avoidance mechanism that takes advantage of the congestion control mechanism of TCP. By randomly dropping packets prior to periods of high congestion, RED tells the packet source to decrease its transmission rate. WRED drops packets selectively BASED ON IP PRECEDENCE. Edge routers assign IP precedences to packets as they enter the network. (WRED is useful on any output interface where you expect to have congestion. However, WRED is usually used in the core routers of a network, rather than at the edge.) WRED uses these precedences to determine how it treats different types of traffic

Question 12

QoS - SHAPING

Answer 12

Traffic shaping retains excess packets in a queue and then schedules the excess for later transmission over increments of time. The result of traffic shaping is a smoothed packet output rate.

Question 13

QoS - POLICE

Answer 13

Traffic policing propagates bursts. When the traffic rate reaches the configured maximum rate, excess traffic is dropped (or remarked)

Question 14

E1

Answer 14

In digital telecommunications, where a single physical wire pair can be used to carry many simultaneous voice conversations by time-division multiplexing, worldwide standards have been created and deployed. An E1 link operates over two separate sets of wires, the line data rate is 2.048 Mbit/s (full duplex, i.e. 2.048 Mbit/s downstream and 2.048 Mbit/s upstream) which is split into 32 timeslots, each being allocated 8 bits in turn. The time slot 0 is devoted to transmission management and time slot 16 for signaling; the rest were assigned originally for voice/data transport.

Question 15

DS0

Answer 15

Digital Signal 0 (DS0) is a basic digital signaling rate of 64 kilobits per second (kbit/s), corresponding to the capacity of one analog voice-frequency-equivalent channel.

Question 16

IBM Informix

Answer 16

IBM Informix is a product family within IBM’s Information Management division that is centered on several relational database management system (RDBMS) offerings. The Informix products were originally developed by Informix Corporation, whose Informix Software subsidiary was acquired by IBM in 2001.

Question 17

Watcher

Answer 17

When you configure Presence in Cisco Unified Communications Manager Administration, an interested party, known as a watcher, can monitor the real-time status of a directory number or SIP URI, a presence entity, from the device of the watcher.

Question 18

Presentity

Answer 18

With the presence feature, a watcher can monitor the status of the presence entity (also called presentity). When you configure BLF/SpeedDial buttons, the presence entity displays as a speed dial on the device of the watcher.

Question 19

Master Agent and Local Agent

Answer 19

DRS has a couple of subsystems that make it work. There is a Master Agent and a Local Agent. The Master Agent does things such as maintaining an XML file, which contains all of the scheduled tasks. And the administrator when they’re using DRS they’re accessing the Master Agent when they are doing things like configuring a backup device. That’s the Master Agent that takes care of that.
The Local Agent however runs the scripts on the server to actually perform the backup and restore processes.

Question 20

DRS

Answer 20

DRS or the Disaster Recovery System is a backup and restore feature of Cisco Unified Communications Manager, Unified Presence, Unity Connection, and it gives us a nice graphical user interface where we can schedule a backup, do a manual backup, monitor the status of a backup. These backups can either be stored on a tape drive or my personal preference is a secure FTP server.
Something to keep in mind about these backups though, these backups are not intended for migration. If you’re upgrading from one version of let’s say Communications Manager to another version and you think you’ll make a backup before you upgrade and then you’ll restore from that backup, that’s probably not going to work because DRS requires that the version of software running on the server match between the server that you backed up from and the server that you’re going to restore to. So it’s really meant for disaster recovery rather than migration.

Question 21

Partitions

Answer 21

Group of numbers (directory numbers, route patterns, translation patterns, etc) with similar reachability characteristics

Question 22

Calling Search Spaces (CSS)

Answer 22

Defines which partitions are accessible to a particular device

Question 23

Time Schedules and Time Periods

Answer 23

Used to allow certain partitions to be reachable only during a certain time of the day

Question 24

Client Matter Codes (CMC)

Answer 24

Used to track calls to certain numbers

A user must enter a client code to track calls to certain clients

Question 25

Forced Authorization Codes (FAC)

Answer 25

Restrict outgoing calls to certain numbers

A user must enter an authorization code to reach the number

Question 26

H.323

Answer 26

ITU standard protocol for interactive conferencing; evolved from H.320 ISDN standard; decentralized dialplan

Question 27

SIP

Answer 27

IETF protocol for interactive and noninteractive conferencing; decentralized dialplan

Question 28

MGCP

Answer 28

IETF standard for PSTN gateway control; centralized dialplan

Question 29

SCCP

Answer 29

Cisco proprietary protocol used between Unified CM and IP phones or to control FXS ports

Question 30

CODECs

Answer 30

Codec - Bandwidth without overhead
G.711 - 64 kb/s
G.722 - 64 kb/s
iLBC - 13.3 kb/s
iSAC - 10-32 kb/s
G.729 - 8 kb/s

Question 31

NTP Reference Clock

Answer 31

A reference clock for device time synchronization. Usually from an external source.
Alternatively, a Cisco router can be configured as a mater NTP server.
The Cisco Unified Communications Manager publisher is the NTP client.

Question 32

DHCP Server

Answer 32

DHCP is a widely used IP standard that can provide the following information to IP phones:

IP address
Subnet mask
Default gateway
DNS servers
TFTP servers

Although it is possible to statically configure IP phones with all that information, it would be time-consuming and error-prone. DHCP is faster, easier, more scalable, and a widely accepted practice. DHCP can be provided by an existing DHCP server (because most deployments already have one), a local router, or even by CUCM itself (although this is not generally recommended for large deployments). Later sections review the configuration of DHCP services in CUCM and router IOS.
CUCM includes a basic DHCP server capability. It is intended to support only IP phones, and not very many of them: only up to 1000 phones. (This is the maximum recommended due to heavy CPU load.) There is no native capability for DHCP server redundancy and only one DHCP server is supported per cluster. Multiple subnets (scopes) can be configured on the server.

Question 33

TFTP Server

Answer 33

The TFTP server provides device configuration files, ringer files, and firmware upgrades to the IP phones. Cisco Unified Communications Manager can provide both - DHCP and TFTP services.

Question 34

DNS Server

Answer 34

DNS provides hostname-to-IP address resolution. DNS services are not critical to IP phones. (In fact, in most deployments, it is recommended to eliminate DNS reliance from the IP phones.) But in some circumstances, it is desirable. A DNS server must be external to the CUCM cluster; DNS is not a service that CUCM can offer.

Question 35

CDP for IP Phone Registration

Answer 35

Cisco Discovery Protocol has several functions for our phones. First of all it’s how they get their VLAN information. What VLAN do I belong to? CDP is also used to tell the switch how much power that device needs – different phones need different wattage. And so CDP, very important, you need to make sure it’s enabled internally. I know for security reasons a lot of times we turn it off at interfaces that face the Internet and that’s fine, we just need to have it on internally for our IP phones.

Question 36

DHCP for IP Phone Registration

Answer 36

another key. Now of course you could statically assign IP addresses to all your IP phones, but I’m thinking that’s not a fun proposition. This is the service which can give your phones the IP addresses.

Question 37

Identification by MAC address for IP Phone Registration

Answer 37

P phones are actually identified in the system by that unique MAC address, not by their IP addresses. That’s how we know our phones. When we configure them, we have to put in the MAC addresses.

Question 38

TFTP for IP Phone Registration

Answer 38

another critical piece to all of this. The TFTP server is how your phones get their specific configuration files. So at first the phone doesn’t know what it is. Once we get that file downloaded now I know what features I have, what Communications Manager servers I registered with, lots of good information in those files.

Question 39

PC port for IP Phone Registration

Answer 39

the phone has a little built-in switch that lets you plug the PC into it on most models. And so now it’s kind of a daisy chain situation where I don’t have to have more than one Ethernet plug in a cubicle or on a wall, I can leverage just the one. I don’t have to have multiple plugs to plug in my PC and my IP phone.
Most IP phones have an Ethernet port for a PC. This allows your computer and phone to share one data connection, routed through the phone and to the computer.

Question 40

Device Settings

Answer 40

Default settings, profiles, templates and common device configuration

Question 41

Device Defaults

Answer 41

Default characteristics of each type of device that registers with Cisco Unified Communications Manager.

Question 42

Common Phone Profiles

Answer 42

Phone configuration parameters assigned to IP phones

Question 43

Phone Security Profile

Answer 43

Security-related settings such as device security mode, CAPF settings, digest authentication settings (for SIP phones only) and encrypted configuration file settings.
Must be applied to each phone.