CCNA VOICE 640-461 CERT GUIDE
CHAPTER 6
 Understanding the CME Dial-Plan

Analog Voice Port Configuration:
• Foreign Exchange Station Ports (FXS): Used to connect analog
devices such as analog phones, fax machines or modems to the
router.
• Foreign Exchange Office Ports (FXO): Used to connect to the
PSTN central office (CO) or a Private Branch Exchange (PBX)
• Use the Router#show voice port summary
Analog Voice Port Configuration:
• Configure FXS:
 Signaling
 Caller ID information
 Call progress tone
Analog Voice Port Configuration:
• Configure FXO:
 Dial-type
 Ring number (rings before answering)
Digital Voice Port Configuration:
• T1 or E1 Voice and WAN Interface Cards (VWIC)
 Must be configured before using (unlike FXO or FXS)
 Can use Channel Associated Signaling (CAS)
 Can also use Common Channel Signaling (CCS)
Router(config)#controller t1 1/0
Router(config-controller)#framing esf
Router(config-controller)#clock source line
NOTE: Better to use line clocking provided from PSTN or provider
Router(config-controller)#ds0-group 1 timeslots 1-24 type fxo-loop-start
Digital Voice Port Configuration:
• Integrated Services Digital Network (ISDN) Primary
Rate Interface (PRI)
 Uses Chanel Associated Signaling (CAS)
Router(config)#isdn switch-type primary-5ess
Router(config)#controller t1 1/0
Router(config-controller)#pri-group timeslots 1-24
Router(config-controller)#show voice port summary
Configuring Dial Peers:
• POTS dial peer: Used to define voice reachability
information for any traditional (analog) connection
• VoIP dial peer: Used to define any voice connection
available through IP addressing
Call Legs:
• Any voice connection too or from a voice port or
connection or voice device




Call
Call
Call
Call
Leg
Leg
Leg
Leg
1:
2:
3:
4:
The
The
The
The
incoming
outgoing
incoming
outgoing
POTS call leg from x1101 on CME_A
VoIP call leg from CME_A to ROUTER_B
VoIP call leg on ROUTER_B from CME_A
POTS call leg to x2510 from ROUTER_B
Configuring POTS Dial Peers for FXS Ports:
CME_A(config)#dial-peer voice 1101 pots
CME_A(config-dial-peer)#destination-pattern 1101
CME_A(config-dial-peer)#port 0/0/0
CME_A(config-dial-peer)#exit
CME_A(config)#dial-peer voice 1102 pots
CME_A(config-dial-peer)#destination-pattern 1102
CME_A(config-dial-peer)#port 0/0/1
Configuring Dial Peers:
• Router#show dial-peer voice summary
Configuring POTS Dial Peer for T1:
Router_B(config)#dial-peer voice 2000 pots
Router_B(config-dial-peer)#destination-pattern 2…
Router_B(config-dial-peer)#no digit-strip
Router_B(config-dial-peer)#port 1/0:23
Configuring VoIP Dial Peer:
CME_A(config)#dial-peer voice 2000 voip
CME_A(config-dial-peer)#destination-pattern 2…
CME_A(config-dial-peer)#session target ipv4:10.1.1.2
CME_A(config-dial-peer)#codec g711ulaw
• If the configured codec does not match the opposite end then the call
will fail. The default codec is G.729
Router_B(config)#dial-peer voice 1000 voip
Router_B(config-dial-peer)#destination-pattern 1…
Router_B(config-dial-peer)#session target ipv4:10.1.1.1
Router_B(config-dial-peer)#codec g711ulaw
Using Dial-Peer Wildcards:
• Period (.): Will match any digit
• Plus(+): matches one or more instances of the preceding digits
• Brackets ([]): Matches a range of digits
• T: matches any dialed number from 0-32 digits
• Carrot (^): Does not match
• Comma (,): Inserts a one-second pause between dialed digits
• Example:
 555[1-3]…




5+23
[14-6]555
55[59]12
[^1-7]..[135]
Matches: 5551…, 5552…, 5553… (Where … is
any three digits)
Matches 5523, 55523, 55523
Matches 1555, 4555, 5555, 6555
Matches 55512, 55912
Matches 8..1, 8..3, 8..5, 9..1, 9..3, 9..5
(Where is any two digits)
Digit Manipulation:
Digit Manipulation Problem:
Digit Manipulation Problem Answer:
North American Dial Plan:
• [2-9]……
• [2-9]..[2-9]……
• 1[2-9]..[2-9]……
• [469]11
• 011T
Used
Used
Used
Used
Used
for
for
for
for
for
7-digit dialing
10-digit dialing
11-digit dialing
service numbers
international dialing
North American Dial Plan:
Router(config)#dial-peer voice 90 pots
Router(config-dial-peer)#description Service Dialing
Router(config-dial-peer)#destination-pattern 9[469]11
Router(config-dial-peer)#forward-digits 3
Router(config-dial-peer)#port 1/0:1
Router(config-dial-peer)#dial-peer voice 91 pots
Router(config-dial-peer)#description 10-Digit Dialing
Router(config-dial-peer)#destination-pattern 9[2-9]..[2-9]……
Router(config-dial-peer)#forward-digits 10
Router(config-dial-peer)#port 1/0:1
Router(config-dial-peer)#dial-peer voice 92 pots
Router(config-dial-peer)#description 11-Digit Dialing
Router(config-dial-peer)#destination-pattern 91[2-9]..[2-9]……
Router(config-dial-peer)#forward-digits 11
Router(config-dial-peer)#port 1/0:1
Router(config-dial-peer)#dial-peer voice 93 pots
Router(config-dial-peer)#description International Dialing
Router(config-dial-peer)#destination-pattern 9011T
Router(config-dial-peer)#prefix 011
Router(config-dial-peer)#port 1/0:1
Private Line Automatic Ringdown (PLAR):
Router(config)#voice-port 2/0/0
Router(config-voiceport)#connection plar 1500
Router(config-voiceport)#voice-port 2/0/1
Router(config-voiceport)#connection plar 1500
Call Processing:
• Most specific pattern wins
• Once a match is found the call is processed
Router(config)#dial-peer voice 1 voip
Router(config-dial-peer)#destination-pattern 555[1-3]…
Router(config-dial-peer)#session target ipv4:10.1.1.1
Router(config-dial-peer)#dial-peer voice 2 voip
Router(config-dial-peer)#destination-pattern 5551…
Router(config-dial-peer)#session target ipv4:10.1.1.2
If a user dials 5551234 dial-peer 2 will be used because it is a more
specific match
Call Processing:
• Most specific pattern wins
• Once a match is found the call is processed
Router(config)#dial-peer voice 1 voip
Router(config-dial-peer)#destination-pattern 555[1-3]…
Router(config-dial-peer)#session target ipv4:10.1.1.1
Router(config-dial-peer)#dial-peer voice 2 voip
Router(config-dial-peer)#destination-pattern 5551…
Router(config-dial-peer)#session target ipv4:10.1.1.2
Router(config-dial-peer)#dial-peer voice 3 voip
Router(config-dial-peer)#destination-pattern 5551
Router(config-dial-peer)#session target ipv4:10.1.1.3
If a user dials 5551234 dial-peer 3 will be used because it is a more
specific match. Router will drop the last three digits and only route the
5551 (Useful for emergency calls)
Matching Inbound and Outbound Dial Peers:
1. Match the dialed number (DNIS) using the incoming called
number dial peer
2. Match the called ID information (ANI) using the answeraddress dial-peer configuration
3. Match the caller ID information (ANI) using the destinationpattern dial-peer configuration
4. Match an incoming POTS dial peer by using the port dial-peer
configuration
5. If no match has been found using the previous four methods,
use dial peer 0
Call Leg 1:
1. (No Match) 2510 The dialed number does not match an incoming
called-number dial peer
2. (No Match) x1101 Caller ID information (ANI) does not match the
answer-address dial peer configuration on CME_A
3. (No Match) x1101 Caller ID information (ANI) does not match the
destination-pattern dial peer configuration on CME_A
4. (Match) x1101 comes in FXS port 1/0/0 which matches an incoming
POTS dial peer on CME_A by using the port dial peer configuration
command
Call Leg 3:
1. (No Match) 2510 The dialed number does not match an incoming
called-number dial peer on ROUTER_B
2. (No Match) x1101 Caller ID information (ANI) does not match the
answer-address dial peer configuration on ROUTER_B
3. (Match) x1101 Caller ID information (ANI) does match the destinationpattern dial peer configuration command for the VoIP dial peer 1101 on
ROUTER_B
Call Leg 4:
1. (No Match) 2510 The called number does not match an incoming
called number
2. (No Match) x1101 Caller ID information (ANI) does not match the
answer-address dial peer configuration on ROUTER_B
3. (No Match) x1101 Caller ID information (ANI) does not match the
destination-pattern dial peer configuration
4. (No Match) x1101 did not come into a POTS interface (FXS, FXO, E&M,
Voice BRI/T1/E1 digital interface that could be matched using the port
command. It came via VoIP
5. (Match) Because ROUTER_B could not find a match it will use dial peer
0
Dial Peer 0:
• Default Dial Peer
 Uses any voice codec (Not hard coded)
 No DTMF relay: DTMF relay sends dial tones outside of
the audio stream
 IP Precedence 0: Strips all QoS markings. Calls will now
be sent as if they were normal data
 Voice Activity Detection (VAD) enabled: Allows bandwidth
savings by not transmitting dead time
 No Resource Reservation Protocol (RSVP) support: The
router will not reserve end-to-end bandwidth
 Fax-rate voice: The router will limit fax bandwidth to
that of the VoIP codec. Can devastate fax calls
 No application support: calls cannot be referred to outside
applications
 No Direct Inward Dial (DID) support: Cannot use the DID
feature to forward calls to an internal device from an PSTN
source
Digit Manipulation:
• prefix digits: Allows for digits to be added to be specified
• forward-digits number: Allows for the number of digits that will
be forwarded
• [no] digit-strip: Enables (default) or disables digit stripping
• num-exp: Transforms any number dialed that matches pattern.
Example: num-exp 4… 5…
Call 4321 converted to 5321
Example: num-exp 0 5000
Call 0 converted to 5000
• voice translation profile: Allows a translation profile of up to 15
rules to be transform the number
POTS Failover:
• If the VoIP network fails, the phone system should
automatically switch to the POTS system
POTS Failover Configuration:
Arizona(config)#dial-peer voice 10 voip
Arizona(config-dial-peer)#destination-pattern 6…
Arizona(config-dial-peer)#session target ipv4:10.1.1.2
Arizona(config-dial-peer)#preference 0
Arizona(config-dial-peer)#dial-peer voice 11 pots
Arizona(config-dial-peer)#destination pattern 6…
Arizona(config-dial-peer)#port 1/0:1
Arizona(config-dial-peer)#preference 1
Arizona(config-dial-peer)#no digit-strip
Arizona(config-dial-peer)#prefix 1512555
Texas(config)#dial-peer voice 10 voip
Texas(config-dial-peer)#destination-pattern 5…
Texas(config-dial-peer)#session target ipv4:10.1.1.1
Texas(config-dial-peer)#preference 0
Texas(config-dial-peer)#dial-peer voice 11 pots
Texas(config-dial-peer)#destination pattern 5…
Texas(config-dial-peer)#port 1/0:1
Texas(config-dial-peer)#preference 1
Texas(config-dial-peer)#no digit-strip
Texas(config-dial-peer)#prefix 1480555
Using num-exp to Transform numbers:
Router(config)#voice-port 1/0/1
Router(config-voiceport)#connection plar 0
Router(config-voiceport)#exit
Router(config)#num-exp 0 5000
• Connects any dialed 0, to the receptionist within the company at
extension 5000
POTS Lines for Emergency Calls:
Remote_RTR(config)#dial-peer voice 10 pots
Remote_RTR(config-dial-peer)#destination-pattern 911
Remote_RTR(config-dial-peer)#port 1/0/0
Remote_RTR(config-dial-peer)#no digit strip
Remote_RTR(config-dial-peer)#dial-peer voice 11 pots
Remote_RTR(config-dial-peer)#destination pattern 9911
Remote_RTR(config-dial-peer)#port 1/0/0
Remote_RTR(config-dial-peer)#forward-digits 3
Remote_RTR(config-dial-peer)#dial-peer voice 12 pots
Remote_RTR(config-dial-peer)#destination pattern 911
Remote_RTR(config-dial-peer)#port 1/0/1
Remote_RTR(config-dial-peer)#no digit-strip
Remote_RTR(config-dial-peer)#dial-peer voice 13 pots
Remote_RTR(config-dial-peer)#destination pattern 9911
Remote_RTR(config-dial-peer)#port 1/0/1
Remote_RTR(config-dial-peer)#forward-digits 3
POTS Lines for Emergency Calls:
Translation Rule:
• Define the rules that dictate how the router will transform
the number
• Associate the rules to a profile
• Associate the profile to a dial peer
• Format: rule 1 /match/ /set/
Router(config)#voice translation-rule 1
Router(config-translation-rule)#rule 1 /6/ /5/
• Match the number “6” and replace with a “5”
Translation Profile:
• Define the rules that dictate how the router will transform
the number
• Associate the rules to a profile
• Associate the profile to a dial peer
Router(config)#voice translation-profile CHANGE_DID
Router(config-translation-profile)#translate called 1
Router(config-translation-profile)#dial-peer voice 100 pots
Router(config)#dial-peer voice 100 pots
Router(config-dial-peer)#translation-profile incoming CHANGE_DID
Translation Profile:
Translation Order:
Applied 1st
num-exp
Applied 2nd
Automatic digit strip
(POTS dial peers)
Applied 3rd
Voice translation profiles
Applied 4th
Prefix digits
Applied 5th
forward-digits
Class of Restriction (COR):
• Prevent employees from making international calls but allow
management
•Block high cost numbers such as 1-900
•Prevent certain internal phones from reaching executive office
numbers
Class of Restriction (COR):
• Defining COR List Tags
Router(config)#dial-peer cor custom
Router(config-dp-cor)#name 911
Router(config-dp-cor)#name LOCAL
Router(config-dp-cor)#name LD
• Create Outgoing COR List
Router(config)#dial-peer cor list 911-CALL
Router(config-dp-corlist)#member 911
Router(config-dp-corlist)#exit
Router(config)#dial-peer cor list LOCAL-CALL
Router(config-dp-corlist)#member LOCAL
Router(config-dp-corlist)#exit
Router(config)#dial-peer cor list LD-CALL
Router(config-dp-corlist)#member LD
Router(config-dp-corlist)#exit
Class of Restriction (COR):
• Defining Incoming COR Lists
Router(config)#dial-peer cor list 911-ONLY
Router(config-dp-corlist)#member 911
Router(config-dp-corlist)#exit
Router(config)#dial-peer cor list 911-LOCAL
Router(config-dp-corlist)#member 911
Router(config-dp-corlist)#member LOCAL
Router(config-dp-corlist)#exit
Router(config)#dial-peer cor list 911-LOCAL-LD
Router(config-dp-corlist)#member 911
Router(config-dp-corlist)#member LOCAL
Router(config-dp-corlist)#member LD
Router(config-dp-corlist)#exit
Class of Restriction (COR):
• Assigning Outbound and Inbound COR Lists
Router(config)#dial-peer voice 10 pots
Router(config-dial-peer)#corlist outgoing 911-CALL
Router(config-dial-peer)#exit
Router(config)#dial-peer voice 11 pots
Router(config-dial-peer)#corlist outgoing LOCAL-CALL
Router(config-dial-peer)#exit
Router(config)#dial-peer voice 12 pots
Router(config-dial-peer)#corlist outgoing LD-CALL
Router(config-dial-peer)#exit
Router(config)#ephone-dn 1
Router(config-ephone-dn)#corlist incoming 911-ONLY
Router(config-ephone-dn)#exit
Router(config)#ephone-dn 2
Router(config-ephone-dn)#corlist incoming 911-LOCAL
Router(config-ephone-dn)#exit
Router(config)#ephone-dn 3
Router(config-ephone-dn)#corlist incoming 911-LOCAL-LD
Router(config-ephone-dn)#exit
Class of Restriction (COR):
• Rules:
 If there is no outgoing COR list applied then the call is
always routed
 If there is no incoming COR list applied then the call is
always routed
Quality of Service (QoS):
• Lack of bandwidth
• Delay
 Fixed delay
 Variable delay
 Jitter (delay variations)
• Packet loss
•Requirements for VoIP and Video
 End-to-end delay: 150 mSec or less
 Jitter: 30mSec or less
 Packet loss: 1% or less
• Requirements for Data
 Mission-critical applications
 Transactional applications
 Best-effort applications
 Scavenger applications
Quality of Service (QoS) Mechanisms:
• Best Effort: Default method used in every network. No QoS
mechanism is used.
• Integrated Services (IntServ): Works through a system of
reservations reserving bandwidth for applications through the
Resource Reservation Protocol (RSVP). Provides guaranteed
bandwidth. Not scalable
• Differentiated Services (DiffServ): Most popular as it
classifies traffic and places the traffic into cues with “almost
guaranteed” bandwidth. Most used method.
Quality of Service (QoS) Mechanisms:
•
•
•
•
•
Classification and Marking
Congestion Management
Congestion Avoidance
Policing and Shaping
Link Efficiency
 Payload Compression
 Header Compression
 Link Fragmentation and Interleaving (LFI)
Quality of Service (QoS) Mechanisms:
• Queuing Algorithms
 Weighted Fair Queuing (WQF); Balance bandwidth among
all.
 Class-Based Weighted Fair Queuing (CBWFQ): Sets
classes and assigns bandwidth
 Low Latency Queuing (LLQ): Adds priority to CBWFQ
Cisco AutoQoS:
• Automated system by Cisco
 Easy to implement
 Reduces the time of deployment
 Provides configuration consistency
 Reduces deployment cost
 Allows for manual tuning
• First establish a “Trust Boundary”
• AutoQoS uses Cisco Discovery protocol (CDP) so do not disable
on connections that need it!
Cisco AutoQoS Example:
• Serial links must have the bandwidth command configured!
Cisco AutoQoS Configuration Example:
Voice_Switch(config)#interface fa0/3
Voice_Switchr(config-if)#auto qos voip cisco-phone
Cisco AutoQoS Configuration Example:
Router(config)#interface fa0/1
Router(config-if)#auto qos voip trust
Cisco AutoQoS Configuration:
Voice_Switch(config)#interface fa0/3
Voice_Switch(config-if)#description Cisco Phone
Voice_Switch(config-if)#auto qos voip cisco-phone
Voice_Switch(config-if)#interface fa0/1
Voice_Switch(config-if)#description Switch Router Uplink
Voice_Switch(config-if)#auto qos voip trust
Router(config)#interface fa0/0
Router(config-if)#auto qos voip trust
Cisco AutoQoS Configuration:
• auto qos voip: Enable AutoQoS without trusting any markings.
Router will remark all traffic types
• auto qos voip trust: Enable AotoQoS trusting any existing
markings
• auto qos voip cisco-phone: Switch only! Enables AotoQoS and will
trust any existing markings only if CDP detects a Cisco phone
attached
• auto qos voip cisco-softphone: Switch only! Enables AutoQoS
and will trust any existing markings if CDP detects a Cisco
Softphone (IP Communicator)
• New version of AutoQoS is auto discovery! Auto discovery
allows the router to monitor the traffic for an indefinite period
and record traffic patterns and generate a QoS policy that can
be applied
End of Chapter 6