Interview Study Guide

8/3/2019 Interview Study Guide

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oIP General

What’s Cisco Unity?

oice Mail System. I can even be tied in with Microsoft exchange to get an email when someone sends you a voice mail.

What VoIP component can permit or deny a call attempt on the basis of a networks available bandwidth?

atekeeper

What is Vishing?

s a type of phishing attack that uses IP based voice calling

ef:Vishing is the practice of leveraging IP-based voice messaging technologies

rimarily Voice over Internet Protocol, or VoIP) to socially engineer the

ended victim into providing personal, financial or other confidential infor-

ation for the purpose of financial reward. The term ―vishing‖ is derivedom a combination of ―voice‖ and ―phishing.‖

What are three ways you can power a Cisco IP Phone?

PoE b. power adapter c. inline power patch panel

Which DHCP option provides the IP address of a TFTP server to a Cisco Phone?

tion 150 (this is applied under the dhcp pool)

What is RTP and what is this protocol responsible for?

eal-Time Transport Protocol that carries the actual digitized voice samples in a call. It makes sure the receiving end knows the

rrect order of the packets

What is a DSP and what does it do?

gital Signal Processor, it’s a microprocessor residing in Cisco routers or switches that provides voice compression and

cketization services.

How do UDP and RTP operate during a voice call?

voice call uses UDP(user datagram protocol) to operate in real time. Since UDP has no control over the order in which packet

rive at the destination it uses RTP to let the receiving end know the correct order of the packets and not to wait too long for

ckets.

DP VoIP data packets live in Real-Time Transport Protocol packets which are inside UDP-IP packets.

What proprietary signaling protocol is used with Cisco IP phones? What are some other standard signaling protocols?

CCP(Skinny Client control protocol) •others are H.323, Media Gateway Control Protocol(MGCP), Session Initiation Protocol (

)How much bandwidth is consumed with codec G.711 & G.729? G.711(no compression) uses 64 kb/s for a single call while

729 uses 8 kb/s

)How do cisco ip phones seperate voice and data packets?

oice packets will be tagged by the IP phone and data packets will be sent as untagged packets from the IP phone

)What is the difference between a restart and reset on a cisco ip phone? And when or why would you use them?eset- Contacts the DHCP and TFTP server for updating information (longer) •Date and time settings •Network locale •Phone

mware •Source address •TFTP path •URL parameters •User locale •Voicemail access number

estart- Only contacts the TFTP server (faster) •Directory numbers •Phone buttons •Speed-dial numbers

)What interface would you equip a router with if you would like to trunk a small office environment to the PSTN using ana

onnections?

n FXO interface allows an analog connection to be directed at the PSTN's central office or to a station interface on a PBX.

)What are the business benfits of VoIP? •cost savings •rich media services •phone portability •intergartion with other applica

ser contol interface •No geographical boundary •Rich features

)Explain the Cisco IP phone boot process?

hone is powered on

etermines it's voice vlan by using CDP (if CDP is disabled than the vlan must be manually configured on the phone)

he ip phone send a DHCP request that is tagged with the voice vlan

he dhcp server replies with the ip address information along with option 150 which specifies the TFTP Server's IP address

he phone contacts the TFTP server and downloads its firmware and configuration files

he ip phone now knows the primary call processing agent(CPA), usually the subscriber

he ip phone now attempts to contact the primary CPA and attempts to register. If that fails it tries to attempt with the next cpa a

on.

Depth VoIP

What does BAT stand for and what is it used for?

ulk Administration Tool

What’s TFTP's Port Number? 69

What is HTTP's secure port number? 443 and HTTP is 80

What is the name of the website that is used for daily administration of the Call Manager(moves, adds, changes)?



sco Unified CallManager 4.3 Administration, For services? Cisco Unified CallManager 4.3 Serviceability

What is the name of the application program that you could use to "Remote Desktop" from your workstation to a server?

emote Desktop Connection (mstsc from run) & RealVNC

Which cisco call manager application is used to backup, and if necessary, restore a callmanager implementation from that

ckup?

saster Recovery System (DRS)

What are perhaps the two most important parts of call-routing logic in CallManager?(hints: assigned to objects such as ph

d directory numbers. Cisco refers to one of these as "an ordered list" of the other.

oute List •Route Group

How many voice channels are there in an ISDN T1 PRI?

B-channels(64 kbit/s in full duplex)(primary data or voice communication is carried) and one 64-kbit/s D-channel(carries thentrol and signalling information)

How many channels are there in a T1 CAS(Channel Associated Signaling)? 24 Channels(all channels can be used because

the 24 channels are dedicated to just sending signaling information)

)Name the most common or prevalent types of line coding and framing?

Line Coding - Bipolar 8-zero substitution (B8ZS)(used most often)(fixes bipolar violation)

ne Coding - AMI

aming - Super frame (SF): Combines 12 standard 193-bit frames into a super frame

Framing - Extended super frame (ESF) - Combines 24 standard 193-bit frames into an extended super frame(most commonly

ed in real world situations)

)What does PoE stand for?

ower Over Ethernet

)What are two pieces of information you need in order to insert a phone in the Call Manager?

AC address •Phone type

)What is the symptom of a phone which has been inserted into the call manager with an incorrect model number?

pulls a valid IP address, but phone's status will be "Not Registered" in Cisco Unified CallManager Administration

)What is the reason that a phone would display a "Registration Rejected" message?

hone isn't configured in CallManager •Wrong IP Phone Type

)Name as many things as possible that can cause simplex(half-duplex) or one way audio in a VoIP Network?

syncronous routing •outdated firmware in Routers, VOIP phones, Firewalls, etc •configuration(particularly NAT)

)Name some things that PVDMs do for you in a VoIP Network?Packet Voice DSP Modules

rovides the ability to increase the voice processing capabilities within a single network module

sed for voice termination (one leg on TDM(time-division multiplexing) interface and the second leg on VoIP)

rovides hardware media resources such as transcoding, mtp or conference bridges)What are the three items necessary for what is traditionally termed a Hunt Group, in order of creation?

ne group(you also add the DNs when creating this)

unt list

unt pilot(the number someone dials to start the hunt group/pointer)

ocess of a dialed number?

all matches a pattern

attern points to a route list

he route list sends the call to the first route group in it's list

he route group points to one or more gateways and sends the call to the first gateway in the group

)In call manager, what three objects can effectivly reserve a directory number?

P Phone •Voice Mail Port •Intercom

e IP phone, a Cisco IP SoftPhone, a fax machine, or an analog phone attached to a gateway

)What is the most accurate way of determining what Directory Numbers are available in a CallManager 4 environment?

earch the Route Patterns and find out which route pattern has the ―Route Option‖ Block this pattern, and has ―Unallocated Num

lected (there’s no need to create a dial pattern for DNs to be reachable inside the same cluster)

ime-division multiplexing (TDM) -- A common technology used to send multiple conversations over a single connection

oute Pattern—In Voice Over IP (VoIP), route patterns are the equivalent of static routes. The only difference is the route patt

int to E.164 numbers instead of the IP address. The Route Pattern is a specific number or, more commonly, a range of dialed

mbers that are used to route calls to a device directly, such as a DT-24+ or a voice-capable router, or indirectly through a Rou

st. For example, 1XXX signifies 1000 through 1999. The X in 1XXX signifies a single digit, a placeholder or wildcard. There ar

her such placeholders that are to be introduced later, such as @, ., and !). A Route Pattern does not have to be unique within

artition, as long as the Route Filter is different. In general, a Route Pattern matches the dialed number for external calls, perfo

git manipulation(optional), and points to a Route List for routing.



oute List—Formerly called Route Point, the Route List allows Cisco CallManager to hunt through a list of Route Groups in a

nfigured order of preference. A Route List consists of an ordered list of Route Groups. Route Lists expand the Route Groups

ncept and allow the user to order and prioritize your route groups. Multiple Route Lists can point to the same Route Groups. A

oute List chooses a path for call routing and points to prioritized Route Groups.

oute Group—Route Groups and Route Lists work together to control and enhance external call routing. A Route Group is a l

e or more gateways, or ports on gateways, that are seen as equal access. It is analogous to a trunk group in traditional PBX

rminology. For instance, one can have two Primary Rate Interface (PRI) circuits to the same carrier that can be used arbitraril

teway, or a particular port on a gateway, can only be added to one Route Group.

evice—A device, in this sense, is a gateway that is Skinny-based (DT-24+, AS/AT, or Catalyst 6000 gateways), MGCP-base

G200), or H.323-based (all Cisco IOS® gateways and other Cisco CallManagers). These are all devices to which a Route Gro

n point. They do not include Skinny-based or H.323-based endpoints, such as IP phones or NetMeeting clients.ranslation Pattern—A Translation Pattern is used in order to translate called (Dialed Number Identification Service [DNIS]) a

lling (automatic number identification [ANI]) numbers before the call is routed. For example, you can have calls come into a s

mbers 919 392-3XXX that must be translated to a set of IP phones that are in the 2XXX range. In Cisco CallManager, you se

Translation Pattern for 919 392-3XXX that changes the leading 919 392-3 to just 2, while the rest of the digits are left intact. T

e call is routed to the appropriate IP phone. Translation Patterns are used only for true translations and must not be used as a

mple way to strip or prefix digits.

oute Filter—A Route Filter can be used not only to restrict dialing but also to identify a subset of a pattern with a placeholder

hen the @ placeholder is used in the North American Dialing Plan. Cisco CallManager identifies tags in each number,

ernational-Access, Area code, and Office-Number. For example, you can use it to block 900 area codes. It can also be used

njunction with Partitions and Calling Search Spaces in order to set up complex rules. For example, you could set up Route Fi

at allow an Executive user group to dial any number, which includes international numbers, but restrict a Staff user group to o

cal numbers or long distance calls and restrict a Guest user group to only dial local numbers, 911, and 800 numbers.

artition—A Partition is a logical group of Directory Numbers and Route Patterns with similar characteristics for reachability. F

mplicity, these are usually named for their characteristics, such as "NYLongDistance" and "NY911." When a DN or Route Patt

aced into a certain Partition, it creates a rule about who can call that device or Route List.

alling Search Space—The Calling Search Space is a group of Partitions to search, when you make a call, that defines what

mbers a device can call. For instance, an IP phone number that has an Executive Calling Search Space when it initiates a ca

ght have "NYInternationalCall," "NYLongDistance," "NYLocalCall," and "NY911" Partitions available to search. An IP phone

mber that has a Guest Calling Search Space can only be allowed to search "NYLocalCall" and "NY911". If that number tries t

international number, it does not find a match and the call is not routed. The Calling Search Space defines what Directory

umbers and Route Patterns can be called.

unting—Allows a call to be directed to a list of line groups where each group can independently use one of three algorithms,

own as broadcast, top down, or circular:* Hunting commences when a hunt pilot number associated with a hunt list is called.

* The hunt pilot can be called directly or can be reached through forwarding.

* While hunting, the forwarding fields of the hunt parties are ignored. The determination of which phone to ring next is determ

the line groups within the hunt list.

Media Termination Point (MTP) software device allows Cisco CallManager to relay calls that are routed through SIP or H.3

dpoints or gateways. MTP, a Cisco software application, installs on a server during the software installation process. You mu

tivate and start the Cisco IP Voice Media Streaming App service on the server on which you configure the MTP device.

hedule a conference? You need Meeting Place

Max delay IP world? •40ms for any two servers inside the same cluster •150ms from phone to phone

ublisher – master server, master database for all servers in a cluster

ubscriber – backup,

luster – can be 1 physical server but you need 1 publisher and 1 subscriber to be consider a cluster. Maximum of 20 servers

uster, Maximum of 8 servers can be used for call processing.

onferencing – mixing multiple audio streams into a single stream

ateway – converts ISDN(from PSTN) signaling messages into a VoIP signaling protocol(H.323 or SIP)

.323 – Cisco

IP – used in a multi vendor environment

atekeeper – Provides CAC (call admission control), bandwidth control, management, and address translation. Prevents calls

ersubscribing the WAN bandwidth.



*Senior Network Administrator Interview***

eadership Questions

Are you willing to move anywhere in Iraq if we need you to? Yes

Tell us about yourself and background(few minutes)(question is used for breaking the ice)?

What are the 6 levels of progressive discipline?

vel 1—Verbally counsel the employee. Informal initial counseling for minor issues thatclude but are not limited to tardiness, timeliness of task completion, or dress or uniform

sues, unrelated to safety. Make a written note of the date, time, and topic of the verbalunseling.vel 2—Issue a verbal warning. Used when the employee has been verbally counseledleast twice but has not improved. Supervisor documents problem, actions to be taken,

meframe for improvement, and follow-on counseling date in a Memo for Record. Theemo for Record can be placed in the employee’s personnel file. vel 3—Issue a written warning. Discipline for Class C Misconduct or for repetitivehavior identified in the Level 2 verbal warning.vel 4—Place the employee on suspension. Discipline for Class B Serious Misconduct orpetitive behavior identified in the level 3 written warning. HR prepares or approves thespension letter.vel 5—Issue a final written warning/last chance agreement. Discipline for Class A,excusable Misconduct; Class B, Serious Misconduct; or repetitive behavior identified in thevel 4 suspension. HR approves or prepares the last chance agreement.vel 6—Terminate the employee. Discipline for Class A, Inexcusable Misconduct orpetitive behavior identified in level 5 written warning/last chance agreement. Terminationsust be approved by the Program Manager and Director, HR before taking action. HR willsist in writing the termination letter.

In a diverse atmosphere, what are the team leader’s responsibilities in building a team?

Lead by example and do what is right legally, ethically, and morallyBuild trust and relationships: team members should want to be part of the teamEnsure the team understands its purpose, i.e., the job and why what the team does isportantEnsure every team member understands their role and responsibilities and those of their fellow

am members

Ensure the team understands the standards for job performance and enforce themncourage team members to work togetheregrate new members into the team quickly

ake team members feel that they are valuable contributors to accomplishing the jobompliment team members publically, criticize them in privatet the team have the credit for a job well done

se other team members to train the team but be sure that they are ready and have rehearsedeir traininghen mistakes happen, figure out what went wrong and how to fix or avoid the sameoblem in the future; do not assign personal blame—focus on what actions should beken to fix the situationeely forgive shortcomings in pursuit of success—don’t hold mistakes against an employee ho is trying to do the right thing

eate a climate that expects good performance, recognizes superior performance, andes not accept poor performance

stablish an environment where professional and personal relationships do not clashmpower subordinates—give them a job, the necessary authority, and let them do theork; oversee those who need it to be sure that they are successfulevelop subordinates and give them constructive feedback—both positive and negativeake care of team members’ morale, physical condition, safety, and professional velopment, i.e., ensure that team members have the proper tools for the job or thatere is water available if working in a hot climateeep team members informed of actions and results; it allows team members to plan whateds to be done and adjust to change. Explaining a decision and the reasons for it showsam members that they are appreciated and trustedalance the mission with the welfare of the team members

esolve conflict—discuss what is causing it and how to fix it with the team membersvolved



nticipate and manage change

echnical Questions

What is a /23? 255.255.254.0

What is 255.255.255.224? /27

Used to stop Ethernet collisions? CSMA/CD Carrier Sense Multiple Access/Collision Detection

Describe a VLAN? A VLAN is a virtual LAN that breaks up a network logically. Separates broadcast domains.

VTP modes(VLAN Trunking Protocol)?

erver Mode Once VTP is configured on a Cisco switch, the default mode used is Server Mode. In any given VTP managemen

main, at least one switch must be in Server Mode. When in Server Mode, a switch can be used to add, delete, and modify VL

d this information will be passed to all other switches in the VTP management domain. Client Mode When a switch is configu

use VTP Client Mode, it is simply the recipient of any VLANs added, deleted, or modified by a switch in Server Mode within th

me management domain. A switch in VTP client mode cannot make any changes to VLAN information. Transparent Mode A

witch in VTP Transparent Mode will pass VTP updates received by switches in Server Mode to other switches in the VTP

anagement domain, but will not actually process the contents of these messages. When individual VLANs are added, deleted

odified on a switch running in transparent mode, the changes are local to that particular switch only, and are not passed to oth

witches in the VTP management domain.

UDLD (Unidirectional Link Detection)? What does it detect? It detects loops.

What does Spanning Tree Portfast do? It will immediately transition a port to the forwarding state and not attempt to detect a

witching loop

How do you erase a VLAN? sw1(config)#no vlan 2-1000 or delete the vlan.dat file from flash and reload switch

Etherchannel? provide redundancy and port aggregation, it’s a way to “bundle” multiple physical links into a single logical li

W1(config)#interface range fa0/10 - 12

W1(config-if-range)#no shut

W1(config-if-range)#channel-group 1 mode on

W2(config)#interface range fa0/10 - 12W2(config-if-range)#no shut

W2(config-if-range)#channel-group 1 mode on

W1#show etherchannel summary

W1#show etherchannel load-balance

. What is VTP pruning? How do you implement it? VTP pruning is used to stop the forwarding

roadcast from a host in a specific VLAN to every switch trunk. It will only allow broadcast t

e sent where needed. To implement it you will type “vtp pruning” in global config mode in the

witch that is the VTP server. *”show interface trunk” will show you what vlans are allowed ovhat trunk.

. How to specify Root Bridge in STP? In global config mode type “spanning-tree vlan x root

rimary” or “spanning-tree vlan x priority <number>” (where the number is lower than the defau

alue of 32,768)

. Describe password recovery for a 3550? Cycle the power while holding down the mode button

ait 10 seconds before releasing, type “flash_init, dir flash:, rename flash:config.text

lash:config.old, boot, copy flash:config.old run, change password by “enable password ****” ainally “copy run start”

. Configure default static route? ip route 0.0.0.0 0.0.0.0

. Share routing into between routing protocols?

. What is AAA? Why do we use it? Authentication, authorization , and Accounting. It is used

switch or router to grant permission to a client.



6. How to prevent machines from connecting to our network? Port security/mac address sticky o

ing a radius server using 802.1x

. What does the provision number mean in VTP for a client? It lets the clients know if they

ave an updated copy of the vlan.dat file. The higher the revision number the newer the copy.

. Pre-reqs for SSH? First you need to create a domain name for the device, in global config

ode type “ip domain-name <domainname.net>”, then generate rsa key, type “cryto key generate r48”, go to “line vty 0 4” and type “transport input ssh”

9. HSRP(hot standby routing protocol) need 3 things? Virtual IP address, virtual MAC address,

nd atleast two devices that belong to the group

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