Call Flows in CUC Systems Flashcards
1
Q
By default, which does CUCM use to define servers to phones in configuration files: DNS names or IP addresses?
A
DNS names
2
Q
Where do calls placed from a remote site in a centralized call model go to access the PSTN?
A
They can be routed out either the branch gateway or from the main location gateway.
3
Q
Name two items that must be configured on CUCM for SRST to work as expected.
A
- Extensions supported by SRST should have CFUR set up to reach them when their branch is down.
- The call-routing table should include a PSTN gateway and digit manipulation to support the CFUR numbers.
4
Q
How many remote locations are supported in a CUCM cluster?
A
1,000
5
Q
How many H.323 or MGCP gateways are supported in a CUCM cluster?
A
1,100
6
Q
What is the maximum number of phones supported in SRST on a branch router (3945E)?
A
1,500
7
Q
Name the two methods of providing CAC.
A
CUCM location-based CAC and RSVP.
8
Q
Name two protocols that CUCM can use to control Cisco voice gateways.
A
MGCP and SCCP
9
Q
Which calling model is simpler: centralized multi-site or distributed multi-site?
A
Centralized multi-site
10
Q
Name three protocols used for signaling between CUCM clusters in a distributed multi-site model.
A
SIP, H.323, ICT (Inter-Cluster Trunk).
11
Q
What device type allows scalability of distribute multi-site architectures to thousands of facilities?
A
Gatekeepers
12
Q
What configuration option is needed to implement AAR? How does it help?
A
AAR groups are needed to manipulate dialed digits for routing over the PSTN.
13
Q
What does AAR stand for?
A
Automated Alternate Routing
14
Q
What are HEHO and TEHO?
A
Head-end hop-off and tail-end hop-off refer to PSTN access at the local and remote locations for a call.
15
Q
An end-to-end call between IP phones attached to separate CME routers requires how many dial peer statements?
A
Four
16
Q
What type of CME dial peer is used for connections via an FXO/FXS port?
A
POTS
17
Q
Give the CME commands that configure dial peer #1 for extension 7777 on the FXS interface at location 0/0/1.
A
(config)# dial-peer voice 1 pots
(config-dial-peer)# destination-pattern 7777
(config-dial-peer)# port 0/0/1
18
Q
Give the command that shows what voice ports are installed on a router.
A
show voice port summary
19
Q
Name the three areas of configuration on FXS ports.
A
Signaling
Call progress tones
Caller ID information
20
Q
What are the two signaling options for FXS ports?
A
Loop start and ground start
21
Q
Give the commands that tell a router to use loop start signaling for FXS port 0/0/0.
A
(config)# voice-port 0/0/0
(config-voiceport)# signal loopStart
22
Q
Give the commands that tell a router to use USA call progress tones on FXS port 0/0/0.
A
(config)# voice-port 0/0/0
(config-voice-port)# cptone US
23
Q
Give the commands that tell a router to use the number 555-1000 for the Caller ID number on FXS port 0/0/0.
A
(config)# voice-port 0/0/0
(config-voice-port)# station-id number 5551000
24
Q
What two configuration options are available on FXO ports that are not on FXS ports? Give the options, associated commands, and defaults.
A
Dial type specifies DTMF or pulse. The command is dial-type with a default of dtmf.
Ring number specifies the number of rings before the router answers the call. The command is ring number with a default of 1.
25
Give the command that configures all the timeslots on a T1 CAS interface for FXO loop start signaling.
(config-controller)# ds0-group 1 timeslots 1-24 type fxo-loop-start
26
Give the command that configures a full CCS T1 for PRI signaling.
(config-controller)# pri-group timeslots 1-24
27
What must be configured before a router will accept a CCS T1 configuration for PRI?
The ISDN switch type
28
You've entered the configuration command that sets all the channels in a CCS T1 for PRI, but forgot that you don't have enough DSPs to support a full T1. How will the router respond?
It returns an error message that includes the number of timeslots you can use.
29
Give the command that provides a list of all dial peers configured on the router.
show dial-peer voice summary
30
Give the command that tells the router to display ongoing dial peer matching.
debug voip dialpeer
31
How does a router differ in its treatment of VoIP and POTS dial peers? How can this be changed?
By default, the router strips all non-wildcard digits from matched POTS dial peers. To keep them, use the command no digit-strip.
32
Give the commands that tell a router to create dial peer #2000 to match all extensions from 2000-2999. Calls to those extensions should go to 10.1.1.2 via G.711 mu-law.
(config)# dial-peer voice 2000 voip
(config-dial-peer)# destination-pattern 2...
(config-dial-peer)# session target ipv4:10.1.12
(config-dial-peer)# codec g711ulaw
33
What is the default CME codec for VoIP dial peers?
G.729
34
Use a wildcard to give a router destination pattern that matches 5523, 55523, and 555523.
5+23
35
Give the destination pattern wildcard that matches any number up to 32 digits.
T
36
What is the default T.302 interdigit timeout for a CME router?
10 seconds
37
You've created a POTS dial peer on a router for x11 calls using the destination pattern 9[469]11. What command should be added to the dial peer configuration for this to work?
(config-dial-peer)# forward-digits 3
38
You've created a POTS dial peer for international calls using the destination pattern 9011T. What additional dial peer configuration command should be added for this to work?
(config-dial-peer)# prefix 011
39
What command configures a voice port to automatically call extension 1102 when the phone is picked up?
(config-voiceport)# connection plar 1102
40
Name the two primary rules for dial peer matching in CME.
1. The most specific destination pattern always wins.
| 2. When a match is found, the router immediately processes the call.
41
Other than setting up a hotline, when would one want to configure PLAR on an FXO/FXS port? Why?
When all incoming calls on an FXO port should be routed to a certain extension. POTS lines don't provide the called number, without PLAR, the router won't know where to send the call and will wait for caller input.
42
Give the command that tells a router to display the dial peer for a given dialed number.
show dialplan number
43
Name three types of devices a router's VoIP dial peer statements could point to.
1. IP phones
2. CUCM/CME
3. Gatekeepers
44
What does DNIS stand for and what does it indicate?
Dialed Number Identification Service. It's the dialed number.
45
What does ANI stand for? What does it indicate?
Automatic Number Identification. It's the caller ID.
46
In CME, inbound POTS dial peers are associated with the incoming POTS call legs of the __________ router or gateway. Inbound VoIP dial peers are associated with the incoming VoIP call legs of the __________ router or gateway.
originating; terminating
47
Name the five steps CME goes through to find a dial peer match for incoming calls. Include any dial peer configuration commands.
1. Match the DNIS using the dial peer configuration command incoming called-number,
2. Match the ANI using the dial peer configuration command answer-address.
3. Match the ANI using the dial peer configuration command destination-pattern.
4. Match an incoming POTS dial peer using the dial peer configuration command port.
5. Use dial peer 0.
48
What is the Cisco-recommended method of matching incoming dial peers on CME?
The incoming called-number command, because it indicates what the caller wanted to reach.
49
Give an example of when you'd want to use the ANI for incoming dial peer matching on CME.
When there are international customers whose call should be routed based on the callers' assumed language.
50
True or False: Default dial peers can be used for outbound calls.
False. They're for inbound calls only.
51
Give the following settings for incoming calls matched to dial peer 0 by CME:
1. Codec(s)
2. DiffServ for signaling and media
3. VAD support
4. RSVP support
5. Fax relay support
6. IVR support
1. Any codec is supported.
2. AF31; EF
3. VAD is enabled.
4. No RSVP support.
5. No fax relay support.
6. No IVR support.
52
Why can using dial peer 0 on CME create support issues?
Because the settings for two-way streams may be different for the two directions.
53
How is the codec chosen when CME selects dial peer 0?
It is based on the requested codec from the source router.
54
Give the CME command that tells the router to convert any operator calls (dialed 0) to send them to extension 5000.
(config)# num-exp 0 5000
[Note that this is done in global config]
55
Name the two dial peer configuration commands that can be used to provide dynamic WAN-to-PSTN failover. How are they used?
Use the commands preference and prefix. Set the preference to greater than the default of 0 on a POTS dial peer and then use the prefix command to add digits that allow the dialing string to work with the PSTN.
56
Name the three steps in creating a voice translation profile on CME.
1. Define the rules that dictate how the router will perform the transformation.
2. Associate the rules into a translation profile.
3. Assign the profile to a dial peer.
57
Give the command that tells you how voice translation profile profile #1 converts dial string 6546 to another string.
test voice translation-rule 1 6546
58
Give the ordered steps (there are five) that CME follows when converting a dial string in CME.
1. num-exp [remember, this is global, so it makes sense to go first]
2. Automatic dial strip (POTS only)
3. Voice translation profiles
4. prefix
5. forward-digits
59
What file type can you use to import a dial plan into CME via CCP?
CSV
60
Digit-by-digit or full string: Which does CME use to pick a matching outbound dial peer?
Digit by digit
61
Give the command that changes the default CME behavior for choosing between several matched outgoing dial peers.
(config)# dial-peer hunt
The number (0-7) matches a set of policies for choosing between peers.
62
Give the three default steps CME takes in choosing between multiple matching outbound dial peers.
1. Longest match in phone number
2. Explicit preference (the preference command on the dial peer)
3. Random selection in rotary format
63
What two items are required for COR to block a call on CME?
An applied incoming COR list and an applied outgoing COR list. If either is missing, the call is always routed.
64
What CUCM feature is used to implement control of access to the dial plan?
Class of Service
65
What is the CUCM definition of a Partition?
A grouping of things with similar reachability characteristics.
66
How many Partitions exist by default in CUCM? Name them.
One. It's the Null Partition.
67
How many custom Partitions can be created in CUCM?
75
68
What is the CUCM definition of a Calling Search Space?
A list of Partitions that are accessible from a particular device.
69
A Partition can be though of as group of...
...things you can dial.
70
How many CSSs are there on CUCM by default? What's in them?
One. It contains only the Null Partition.
71
CUCM Class of Service is also called what?
Class of Control
72
Name the term for what tracks calls to certain numbers for call accounting and billing.
Client Matter Codes
73
What button entries are used to restrict outgoing calls to certain numbers?
Forced Authorization Codes
74
Describe in one sentence how CSSs and Partitions interact.
If the target that is being dialed does not exist in one of the Partitions in the CSS of the caller, the call will fail.
75
Under what circumstances can identical entities exist in CUCM?
When they are in separate Partitions.
76
When two identical entities exist in CUCM and a device is allowed to call both of them, how does CUCM decide which receives a call when their number is dialed?
It's the first entity listed in the calling device's CSS.
77
How does CUCM behave when a CSS is applied to both a line and the device to which the line is assigned?
The line CSS is processed before the device CSS.
78
When a device has a non-default CSS applied to it, can it reach devices in the Null Partition? Why or why not?
It can, because CUCM places the Null Partition at the end of every custom CSS.
79
Briefly describe the Cisco best practice for performing CUCM CoS using both line and device CSSs. Why is this considered best?
Place any calling restrictions on the line CSS, then permit all calls on the device CSS with routing appropriate to the device's location. This minimizes the number of CSSs one must configure.
80
List the three major areas of call routing.
1. Intrasite routing
2. Intersite routing
3. PSTN routing
81
What must be configured on CUCM for external destinations?
Route patterns
82
Name three types of external destinations that CUCM can route calls to.
1. PSTN
2. Other VoIP domains, e.g., Internet telephony service providers
3. Another CUCM cluster
83
Name three items that comprise the CUCM call routing table.
1. Connected devices
2. DNs of registered IP phones
3. Statically entered route patterns
84
Name five entity types that a call routing target can point at.
1. Phone line
2. Trunk
3. Gateway
4. Feature
5. Application
85
Name five entity types that can be sources of call routing requests.
1. Phone line
2. Gateway
3. External trunk
4. Translation pattern
5. Voice mail port
86
List the two steps in basic CUCM call routing logic when multiple patterns match a routing request.
1. CUCM chooses the entry that matches the dialed string.
| 2. CUCM chooses the entry that matches the fewest strings other than the dialed string.
87
Name the two ways in which SIP dialing can be performed on a phone registered to CUCM.
1. The whole dialed string is sent to CUCM in a single SIP INVITE message.
2. Keypad Markup Language (KPML) is used to send digits one by one.
88
What are SIP dial rules? How do they augment KPML?
SIP dial rules are dialing rules that are processed inside a SIP phone without sending any messages to CUCM. When they match a certain string, they can--for example--deny the call or refer it to CUCM. If CUCM needs more information, KPML can send additional digits one by one.
89
If a user dials x1000 from a SCCP phone, how many interactions take place with CUCM? Explain why.
Five--one off-hook and four individual digits.
90
What functionality would be supported by a null dial string in a CUCM translation pattern?
Private Line Automatic Ringdown (PLAR)
91
What is overlap sending?
It's when CUCM forwards each individual digit to the PSTN as it is dialed.
92
What is overlap receiving?
It's when CUCM collects all digits from an incoming PSTN call before attempting to route the call.
93
What are the two entities a route pattern can point to?
A device (e.g., a gateway) or a route list
94
In CUCM, a _____ _____ points to a _____ _____, which in turn points to a _____ _____, which points to _____.
Route pattern; route list; route group; devices
95
What is the complication with bypassing route lists when using route patterns?
If one bypasses route lists and points directly to a gateway, that gateway cannot also be referenced by a route group.
96
What are the two ways route groups can choose the device to send a call to?
Circular or top-down
97
How does route list logic work in CUCM?
It's top-down. If the first route group is available, it routes the call there.
98
What CUCM feature is used to simplify dial plans when an enterprise has multiple PSTN gateways in multiple locations? How does it do this?
Local route groups are route groups that are defined in the device pool, but referenced by route lists. This decouples the location of a PSTN gateway from route pattern and allows devices in various locations to use the same route patterns and lists, but use local gateways.
99
What's the definition of a hunt group?
A group of lines that are associated with a common number.
100
In CUCM hunt groups, _____ _____ point at _____ _____, which in turn point at _____ _____, which in turn contain _____.
hunt pilots; hunt groups; hunt lists; directory numbers
101
A hunt pilot is defined as...
...an ordered list of line groups.
102
A hunt pilot is defined as...
...the telephone number that has been dialed to invoke the hunting process.
103
Where in the hunting process can the called number and calling number be manipulated?
At the hunt list.
104
What are the two circumstances can cause a hunt group to invoke its destination of last resort? In which two places can they be configured?
1. All hunting options have been exhausted
2. The maximum hunt timer has been reached
They're configured on the hunt pilot, either as a specific destination or as a CFNC option.
105
Name the four call distribution algorithm options for hunt groups.
1. Top-down
2. Circular
3. Longest idle time
4. Broadcast
106
What device property is used to implement CAC?
Location
107
What device property is used to determine the codec that can be used for a given call?
Region
108
In what two places can a device's location be set? When it's set in both places, which takes priority?
1. On the device (takes priority)
| 2. On the device pool
109
A device has its region set. Name the three types of region connections that can affect how calls are handled.
1. Connections within the region
2. Connections to other specific regions
3. Connections to non-listed regions
110
State the rule that describes region-based codec selection.
Devices will use the best codec that is supported by both devices and does not exceed the bandwidth requirements for the devices' regions.
111
What form of CAC can be used on H.323 trunks in a distributed call processing model?
H.323 gatekeeper CAC
112
What must one often do in CME when deploying COR on an existing dial plan? Why?
Create a more granular dial plan. This allows restrictions on certain types of PSTN calls (LD, international) when previously one could have a catchall route to the PSTN.
113
What is the range, default, and preferred value (higher or lower) of the CME dial peer preference command?
0-10; 0; lower
114
What CME feature allows you to assign a dial peer to multiple interfaces? How many interfaces are supported?
Trunk groups; 64
115
List the two steps in configuring CME trunk groups.
1. Assign ports to a trunk group.
| 2. Assign the trunk group to an outgoing dial peer
116
What is the default call hunting scheme in a CME trunk group?
Least used
117
What dial peer command is used to identify which trunk group is preferred when multiple trunk groups are assigned to a dial peer? What's the range and default?
preference-num; range 1-64 (lower preferred); default 65
118
Give the filenames and purposes of the two applications that make up the B-ACD on CME. What programming language are they written in?
1. app-b-acd-aa is the auto-attendant
2. app-b-acd is the queuing feature
Both are written as Tcl scripts.
119
How many auto attendants and hunt groups are supported on the CME B-ACD?
10 each.
