Cvoice 6.0 S04 L04

Configuring Path Selection

Implementing Dial Plans on Voice Gateways

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-1

Call Routing and Path Selection  Relies on dial peers  Route to – TDM – IP  Cisco IOS associates one dial peer to each call leg

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-2

Matching Dial Peers Incoming Call Leg

IP

Outgoing Call Leg

VoIP H.323 Gateway

POTS

1

PBX

1

Gateway POTS Analog Phone

3 POTS

Cisco Unified CME*/SRST IP Phone © 2008 Cisco Systems, Inc. All rights reserved.

2

2

Gateway with Cisco Unified CME*

Incoming Dial peers

Cisco Unified CM**

3

Outgoing Dial peers

IP

VoIP

POTS

PSTN

**Unified CM = Cisco Unified Communications Manager CVOICE v6.0—4-3

Digit-by-Digit Signaling

PSTN User dials 90114989123456.

/0

0 0/

0/

dial-peer voice 90 pots destination-pattern 9T port 0/0/0:23 dial-peer voice 90110 pots destination-pattern 9011T port 0/0/1:23

© 2008 Cisco Systems, Inc. All rights reserved.

0/1

International Long Distance Carrier

CVOICE v6.0—4-4

Destination Pattern Matching

WAN User dials 5551234. /0

0 0/

0/

0/1

dial-peer voice 1 pots destination-pattern 555 port 0/0/0:23 dial-peer voice 2 pots destination-pattern 555.... port 0/0/1:23

© 2008 Cisco Systems, Inc. All rights reserved.

PSTN

CVOICE v6.0—4-5

Matching Inbound and Outbound Dial Peers Inbound dial-peer matching: •

Called number (DNIS) with incoming called-number

•

Calling number (ANI) with answer-address

•

Calling number (ANI) with destination-pattern

•

For POTS: voice-port matches with dial-peer port

•

Still no match: default dial peer 0 is used

Outbound dial-peer matching: •

Gateway tries to match called number (DNIS) with destinationpattern

•

If multiple matches are found, the lowest preference wins.

•

If equal preferences are found, a random dial peer is chosen.

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-6

Call Routing and Path Selection Commands router(config-dial-peer)#

destination-pattern [+]string[T]

 Defines the destination pattern of a dial peer that will be used during outbound dial-peer matching router(config-dial-peer)#

incoming called-number [+]string[T]

 Specifies the incoming called number that will be used during inbound dial-peer matching router(config-dial-peer)#

answer-address [+]string[T]

 Specifies the incoming calling number will be used during inbound dial-peer matching © 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-7

Call Routing and Path Selection Commands (Cont.) router(config-dial-peer)#

direct-inward-dial

 Uses the inbound POTS DNIS to match the outbound dial peer (usually required for any DID PSTN trunk)  Used to prevent two-stage dialing router(config-dial-peer)#

preference [0-9]

 Specifies the preference of a dial peer; lower number = higher priority, default=0 router(config)#

no dial-peer outbound status-check pots

 Disables status checking of outbound POTS dial peers during call setup; always includes dial peer in call routing, even if POTS status is down; useful for some ISDN links © 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-8

Matching Hunt Group Dial Peers  Longest match  Explicit preference  Random selection  Least recent use

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-9

Best Practices dial-peer voice 1 pots incoming called-number . direct-inward-dial Cisco Unified CM 1 10.10.10.2

Cisco Unified CM 2 10.10.10.3

PSTN dial-peer voice 100 voip Indicates the primary preference 1 Cisco Unified CM cluster destination-pattern 1... session target ipv4:10.10.10.2 Indicates the secondary dial-peer voice 101 voip Cisco Unified CM cluster preference 2 destination-pattern 1... session target ipv4:10.10.10.3

 Default POTS dial peer with the direct-inward-dial attribute  Provide Cisco Unified Communications Manager redundancy

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-10

Path Selection Strategies PSTN Requirement

Dial Plan Components

Site-code dialing

 Call routing and path selection for intersite calls  Digit manipulation to support site-code dialing

Toll bypass

 Call routing and path selection to route intersite calls over WAN links with PSTN fallback  Digit manipulation to route calls over the WAN or PSTN

Tail-end hop-off (TEHO)

© 2008 Cisco Systems, Inc. All rights reserved.

 Call routing and path selection to route PSTN calls over the cheapest possible path  Digit manipulation to support PSTN fallback

CVOICE v6.0—4-11

Site-Code Dialing and Toll Bypass  Site codes are assigned to sites.  Users dial <site code> + <user extension> to reach a user in a specific site. – Site codes should be in a single range, if possible (e.g., 8XX).  The calling number should also include the site code of the calling party. – This can be done via digit manipulation.  Easy way to solve overlapping numbering plan issues.

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-12

Toll Bypass Example 1

WAN is the preferred path with preference 1.

IP WAN

Phone1-1 2001

Phone1-2 2002

San Jose

© 2008 Cisco Systems, Inc. All rights reserved.

PSTN 2 The PSTN path is used if the WAN path is not available.

dial-peer voice 21 voip destination-pattern 2... preference 1 session-target ipv4:192.168.1.1 dial-peer voice 22 pots destination-pattern 2... prefix 14085552 preference 2 port 0/0/0:23

Phone2-1 3001

Phone2-2 3002 Austin

CVOICE v6.0—4-13

Site-Code Dialing and Toll Bypass Example San Jose

Austin

Site Code: 801

2

Site Code: 802

dial-peer voice 802 voip destination-pattern 802…. session target ipv4:10.10.0.1

IP WAN

Phone1-1 rings. Calling number: 8022002 10.10.0.2

dial-peer voice 801 voip destination-pattern 801…. session target ipv4:10.10.0.2

10.10.0.1

R3

R1

Phone1-1 2001

Phone1-2 2002

PSTN 1

Phone2-1 2001

Phone2-2 2002

User dials 8012001.

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-14

Tail-End Hop-Off  Extends the concept of toll bypass  Uses the WAN for PSTN calls as much as possible  Uses PSTN breakouts closest to the final PSTN destination  Uses PSTN paths as possible backup

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-15

TEHO Scenario San Jose

Austin 2

IP WAN

Local San Jose gateway is used as the PSTN breakout. 3

DID: 512555XXXX

DID: 408555XXXX

R1

Phone1-1 2001

Phone1-2 2002

4

The San Jose PSTN phone rings.

© 2008 Cisco Systems, Inc. All rights reserved.

Call is routed to San Jose via the WAN.

R3

PSTN

Phone2-1 2001

1

Phone2-2 2002

User dials 914085550101.

4085550101

CVOICE v6.0—4-16

Configuring Site-Code Dialing and Toll Bypass 1. Configure voice translation profiles for VoIP intersite routing. 2. Define dial peers for VoIP intersite routing. 3. Configure voice translation rules and profiles for PSTN backup routing. 4. Define dial peers for PSTN intersite routing.

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-17

Site-Code Dialing and Toll Bypass Scenario Users should be able to reach other sites via site codes.

San Jose Site code: 801 ext: 2XXX

Austin Site code: 802 ext: 2XXX

IP WAN DID: 512555XXXX

DID: 408555XXXX 10.10.0.1

10.10.0.2

R1

Phone1-1 2001

Phone1-2 2002

R3

PSTN

Phone2-1 2001

Phone2-2 2002

If WAN fails, the PSTN path should be used.

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-18

Step 1: Configure Voice Translation Rules and Profiles for Intersite Routing San Jose Site code: 801 ext: 2XXX

Austin Site code: 802 ext: 2XXX IP WAN DID: 512555XXXX

DID: 408555XXXX 10.10.0.1

10.10.0.2

R1

Phone1-1 Phone1-2 voice translation-rule 1 2001 2002 rule 1 /^2/ /8012/ voice translation-rule 2 rule 1 /^8012/ /2/ voice translation-profile intersite-out translate calling 1 voice translation-profile intersite-in translate called 2 © 2008 Cisco Systems, Inc. All rights reserved.

R3

PSTN

Phone2-1 Phone2-2 voice translation-rule 1 2001 2002 rule 1 /^2/ /8022/ voice translation-rule 2 rule 1 /^8022/ /2/ voice translation-profile intersite-out translate calling 1 voice translation-profile intersite-in translate called 2 CVOICE v6.0—4-19

Step 2: Define Dial Peers for VoIP Intersite Routing San Jose Site code: 801 ext: 2XXX

Austin Site code: 802 ext: 2XXX IP WAN DID: 512555XXXX

DID: 408555XXXX 10.10.0.1

10.10.0.2

R1

Phone1-1 2001

Phone1-2 2002

R3

PSTN

dial-peer voice 8021 voip destination-pattern 8022... incoming called-number 801 session-target ipv4:10.10.0.2 translation-profile incoming intersite-in translation-profile outgoing intersite-out © 2008 Cisco Systems, Inc. All rights reserved.

Phone2-1 2001

Phone2-2 2002

dial-peer voice 8011 voip destination-pattern 8012... incoming called-number 802 session-target ipv4:10.10.0.1 translation-profile incoming intersite-in translation-profile outgoing intersite-out CVOICE v6.0—4-20

Step 3: Configure Voice Translation Rules and Profiles for PSTN Intersite Routing San Jose Site code: 801 ext: 2XXX

Austin Site code: 802 ext: 2XXX IP WAN DID: 512555XXXX

DID: 408555XXXX 10.10.0.1

10.10.0.2

R1

Phone1-1 2001

Phone1-2 2002

voice translation-rule 3 rule 1 /^8022/ /15125552/ voice translation-profile 802PSTN translate called 3 © 2008 Cisco Systems, Inc. All rights reserved.

R3

PSTN

Phone2-1 2001

Phone2-2 2002

voice translation-rule 3 rule 1 /^8012/ /14085552/ voice translation-profile 801PSTN translate called 3 CVOICE v6.0—4-21

Step 4: Define Dial Peers for PSTN Intersite Routing San Jose Site code: 801 ext: 2XXX

Austin Site code: 802 ext: 2XXX IP WAN DID: 512555XXXX

DID: 408555XXXX 10.10.0.1

10.10.0.2

R1

Phone1-1 2001

Phone1-2 2002

dial-peer voice 8022 pots destination-pattern 8022... port 0/0/0:23 preference 1 translation-profile outgoing 802PSTN © 2008 Cisco Systems, Inc. All rights reserved.

R3

PSTN

Phone2-1 2001

Phone2-2 2002

dial-peer voice 8012 pots destination-pattern 8012... port 0/0/0:23 preference 1 translation-profile outgoing 801PSTN CVOICE v6.0—4-22

Outbound Site-Code Dialing Example 1

voice translation-rule 1 rule 1 /^2/ /8022/ voice translation-profile intersite-out translate calling 1 dial-peer voice 8010 voip destination-pattern 8012... session-target ipv4:10.10.0.1 translation-profile outgoing intersite-out

IP WAN

Site code: 801

408-555-2001

2

R1 10.10.0.1

PSTN

voice translation-rule 3 rule 1 /^8012/ /14085552/ voice translation-profile 801PSTN translate called 3 dial-peer voice 8011 pots destination-pattern 8012... preference 1 port 0/0/0:23 translation-profile outgoing 801PSTN © 2008 Cisco Systems, Inc. All rights reserved.

Incoming

Outgoing

DNIS

8012001

8012001

ANI

2001

8022001

1

Site code: 802

R3

2

312-555-2001

Incoming

Outgoing

DNIS

8012001

14085552001

ANI

2001

3125552001

CVOICE v6.0—4-23

Inbound Site-Code Dialing Example voice translation-rule 2 rule 1 /^8022/ /2/ voice translation-profile intersite-in translate called 2 dial-peer voice 8011 voip destination-pattern 8012... session-target ipv4:10.10.0.1 translation-profile incoming intersite-in

Incoming

Outgoing

DNIS

8022001

2001

ANI

8012001

8012001

IP WAN 10.10.0.1 Phone 2-1 2001

San Jose

© 2008 Cisco Systems, Inc. All rights reserved.

PSTN

R3

Phone 2-1 2001

Austin

CVOICE v6.0—4-24

Configuring TEHO 1. Define the VoIP outbound digit manipulation for TEHO. 2. Define the outbound VoIP dial peer for TEHO. 3. Define the outbound POTS dial peer for TEHO.

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-25

TEHO Scenario San Jose

Use the WAN link for calls to the San Jose PSTN.

Austin

IP WAN DID: 512555XXXX

DID: 408555XXXX 192.168.1.1

R1

Phone1-1 2001

Phone1-2 2002

R3

PSTN

Phone2-1 2001

Phone2-2 2002

If the WAN fails, use the Austin PSTN. 4085550100

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-26

Step 1: Define VoIP Outbound Digit Manipulation for TEHO

R3 voice translation-rule 10 rule 1 /^2/ /15125552/ voice translation-profile SJC-TEHO-OUT translate calling 10

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-27

Step 2: Define Outbound VoIP TEHO Dial Peer

R3 dial-peer voice 914081 voip destination-pattern 91408....... session-target ipv4:192.168.1.1 translation-profile outgoing SJC-TEHO-OUT

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-28

Step 3: Define Outbound POTS TEHO Dial Peer

R3 dial-peer voice 914083 pots destination-pattern 91408....... prefix 1408 preference 1 port 0/0/0:23

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-29

Summary  The call routing logic on Cisco IOS routers, using the H.323 or SIP protocols, relies on the dial peer construct.  Routers must match the correct inbound and outbound dial peers to successfully complete a call.  Dial peers in a hunt group are selected according to criteria such as longest match, explicit preference, and random selection.  Best practices include a default POTS dial peer and redundant Cisco Unified Communications Manager servers.  When remote sites are involved, different path selection strategies are required, including site-code dialing, toll bypass, and TEHO.

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-30

Summary (Cont.)  Site-code dialing uses the concept of prefixing a site code in front of the actual extension and can be combined with toll bypass to route calls over a WAN link instead of a PSTN connection.  TEHO extends the concept of toll bypass by routing calls over the WAN to the closest PSTN breakout to avoid costly long distance and international phone charges.  Site-code configuration requires that each site be assigned a unique site code.  TEHO configuration requires that all calls be routed over the WAN unless it is down or has been oversubscribed and blocked by CAC.

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-31

© 2008 Cisco Systems, Inc. All rights reserved.

CVOICE v6.0—4-32