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SIP Support of Take Back and Transfer in the Cisco Unified Contact Center

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SIP Support of Take Back and Transfer in the Cisco Unified Contact Center

Table Of Contents

SIP Support of Take Back and Transfer in the Cisco Unified Contact Center

Feature Description

Basic Take Back and Transfer on SIP Trunks

DTMF Blind Transfer Under INAP Control on SIP Trunks

Network Blind Transfer Under INAP Control on SIP Trunks

Network Consultation Transfer Under INAP Control on SIP Trunks

Benefits

Prerequisites

Restrictions or Limitations

Related Features and Technology

Related Documents

Provisioning Tasks

Provisioning Examples

Software Changes for This Feature

Properties

Troubleshooting the Feature

Obtaining Documentation, Obtaining Support, and Security Guidelines

Glossary


SIP Support of Take Back and Transfer in the Cisco Unified Contact Center


Document Release History

Publication Date
Comments

March 12, 2008

Initial release of document


Feature History

Release
Modification

9.7(3)

This feature was introduced on the Cisco PGW 2200.


This document describes the new feature, SIP support of Take Back and Transfer in the Cisco Unified Contact Center Enterprise (Unified CCE), on the PGW 2200 and includes the following sections:

Feature Description

Provisioning Tasks

Provisioning Examples

Software Changes for This Feature

Troubleshooting the Feature

Obtaining Documentation, Obtaining Support, and Security Guidelines

Glossary

Feature Description

The previously introduced feature, Take Back and Transfer (Phase 2), enables an established call to be taken back and transferred to another party on TDM-based trunks. Digits dialed by the caller in the middle of a call or a number entered by an operator can start the call take back and transfer.

The SIP Support of Take Back and Transfer in the Cisco Unified Contact Center feature enhances the Take Back and Transfer (Phase 2) feature. The new feature provides the capability to support the SIP trunks as the calling party and/or the transferring party for different call transfers.

Figure 1 shows the high-level system diagram for this new feature.

Figure 1 SIP Support of Take Back and Transfer in the Cisco Unified Contact Center

With this new feature, the Cisco PGW 2200 supports the following take back and transfer functions:

Basic Take Back and Transfer on SIP Trunks

DTMF Blind Transfer Under INAP Control on SIP Trunks

Network Blind Transfer Under INAP Control on SIP Trunks

Network Consultation Transfer Under INAP Control on SIP Trunks

To support Basic Take Back and Transfer and DTMF Blind Transfer Under INAP Control on SIP trunks, PGW accepts mid-call DTMF digits from SIP-based transferring parties to start call transfers. Depending on the capabilities of the transferring party, PGW accepts mid-call DTMF digits in

INFO messages

or

Unsolicited NOTIFY messages

No provisioning is required if the transferring party is using INFO messages to send DTMF digits to PGW. If the transferring party is using unsolicited NOTIFY messages to send DTMF digits to PGW, the trunk group property "UnsolicitedNotifyMethod" must be set to 1.

Basic Take Back and Transfer on SIP Trunks

The Basic Take Back and Transfer (TNT) allows the PGW 2200 to receive DTMF digits on specially provisioned outgoing SIP trunk groups. Either attendant can dial DTMF digits during the call to start a blind transfer to the new destination without intervention (there is no way for the caller to know if the new destination can be reached or not).

With this new feature, SIP trunks can serve as the calling parties and the transferring parties for this TNT function. There is no signaling restriction on the transferred-to party. The transferred-to party can operate on any protocol supported by PGW.

You need to provision the mid-call dial plan for this function. The provisioning examples can be found in the "Provisioning Examples" section.

Figure 2 shows the call flow for TNT on SIP trunks.

Figure 2 Basic Tack Back and Transfer on SIP Trunks

DTMF Blind Transfer Under INAP Control on SIP Trunks

The DTMF Blind Transfer Under Intelligent Network Application Part (INAP) Control (iTNT) function pertains to both non-ICM-controlled and ICM-controlled agents. These agents are interconnected by a PRI (Primary Rate Interface), SS7, or SIP interface.

With this new feature, SIP trunks can serve as the calling parties and the transferring parties for this iTNT function. There is no signaling restriction on the transferred-to party. The transferred-to party can operate on any protocol supported by PGW.

Either attendant can dial DTMF digits during the call to start a blind transfer to the new destination without intervention. Cisco Unified Intelligent Contact Management (ICM) instructs the PGW to disconnect the transferring attendant and establish a new outbound call to another attendant group.

iTNT can be used in a multi-PGW environment in which the PGW nodes are interconnected by the EISUP signaling links.

You need to provision the mid-call dial plan for this function. The provisioning examples can be found in the "Provisioning Examples" section.

Figure 3 shows the call flow for iTNT on SIP trunks.

Figure 3 DTMF Blind Transfer Under INAP Control on SIP Trunks

Network Blind Transfer Under INAP Control on SIP Trunks

The Network Blind Transfer (NBT) Under INAP Control function is available only to ICM-controlled agents.

With this new feature, the SIP trunk can serve as the calling party for this Network Blind Transfer Under INAP Control function. There is no signaling restriction on the transferred-to party. The transferred-to party can operate on any protocol supported by PGW.

An operator can input a new target number by using the Cisco Agent Desktop. After analyzing the number it receives from the Cisco Agent Desktop, the ICM instructs the PGW to disconnect the transferring attendant and establish a new outbound call to another attendant group without intervention.

The Network Blind Transfer Under INAP Control function can be used in a multi-PGW environment in which the PGW nodes are interconnected by the EISUP signaling links.

There is no in-band DTMF signal involved, and no special provisioning (such as the mid-call dial plan) is required.

Figure 4 shows the call flow for Network Blind Transfer Under INAP Control on SIP trunks.

Figure 4 Network Blind Transfer Under INAP Control on SIP Trunks

Network Consultation Transfer Under INAP Control on SIP Trunks

The Network Consultation Transfer (NCT) Under INAP Control function is available only to ICM-controlled agents.

With this new feature, SIP trunks can serve as the calling parties for the Network Consultation Transfer Under INAP Control function. There is no signaling restriction on the transferred-to party. The transferred-to party can operate on any protocol supported by PGW.

The operator can hold the current call, initiate a new call attempt, and alternate between the two connections if the new call is successfully connected.

The NCT can be used in a multi-PGW environment.

There is no in-band DTMF signal involved, and no special provisioning (such as the mid-call dial plan) is required.

Figure 5 shows the call flow for Network Consultation Transfer Under INAP Control on SIP trunks.

Figure 5 Network Consultation Transfer Under INAP Control on SIP Trunks

Benefits

Nowadays service providers and many enterprises start to invest in the end-to-end IP contact center architecture. The main benefit of this feature is to enable PGW to support end-to-end SIP call flows in IP call center applications and perform a variety of call transfers upon requests from the ICM. These transfers include Blind Take Back and Transfer, DTMF Blind Transfer Under INAP Control, Network Blind Transfer Under INAP Control, and Network Consultation Transfer Under INAP Control.

Prerequisites

The Cisco PGW 2200 must be running Cisco MGC software Release 9.7(3). Prerequisites for this release can be found in the Release Notes for the Cisco Media Gateway Controller Software Release 9.7(3) at

http://www.cisco.com/en/US/partner/docs/voice_ip_comm/pgw/9/release/note/rn973.html

Restrictions or Limitations

The SIP Support of Take Back and Transfer in the Cisco Unified Contact Center feature has the following limitations:

TCAP dialogues are not failed over. Calls in the connected state are failed over and remain in conversation, but the TCAP dialogue is lost. Calls are released from the connected state in the normal manner upon user request.

Only two-party connected calls are preserved if a call failover occurs. In the absence of a TCAP controlling dialogue after failover (see the first restriction), the PGW cannot receive further instructions in order to process the call.

If the transferring agent is SIP trunk and the transferred-to agent is SIP or H.323 trunk, the transferring agent cannot hear the ring-back tone unless there is a remote ring-back tone.

The codec selection on the three call legs is based on the current simplified best fit practice of using the codec list provided by party A to party C for the B-C call leg setup. When the call is transferred, this same codec is used for the A-C setup. That is, there is no codec renegotiation for either the B-C call leg or the A-C call leg.

No conferencing capability is available.

An H.323 endpoint cannot be a calling party or a transferring party for TNT/iTNT/NBT/NCT.

A call that was subjected to a consultation transfer cannot be serially resubjected to a TCAP-controlled consultation transfer. If the original agent releases the call, a subsequent consultation phase might be required if the new destination agent also requests a consultation transfer call. If this occurs, the PGW rejects the request. However, in this case, the new destination agent can initiate a blind transfer call.

Related Features and Technology

The SIP Support of Take Back and Transfer in the Cisco Unified Contact Center feature is related to the feature, Take Back and Transfer (Phase 2). The new feature enhances its predecessor, Take Back and Transfer (Phase 2).

Related Documents

This document contains information that is strictly related to this feature. The documents that contain additional information related to the Cisco Media Gateway Controller (MGC) are at

http://www.cisco.com/en/US/products/hw/vcallcon/ps2027/tsd_products_support_series_home.html

Provisioning Tasks

There are no additional provisioning requirements associated with NBT or NCT on SIP trunks.

In order for PGW to support TNT and iTNT on SIP trunks, the system changes one sigpath/trunk group property, MidCallServiceCustID. You need to provision a mid-call dial plan for TNT and iTNT. See the "Provisioning Examples" section for detailed provisioning examples.

Furthermore, if you want to use TNT or iTNT when the transferring party is connected to SIP trunks of Cisco Call Manager, you must set the trunk group property UnsolicitedNotifyMethod to 1.

Information about provisioning is available in the Cisco Media Gateway Controller Software Release 9 Provisioning Guide in the following sections:

Planning for Provisioning

http://www.cisco.com/en/US/partner/docs/voice_ip_comm/pgw/9/provisioning/guide/R9PlnPrv.html

MML Basics

http://www.cisco.com/en/US/partner/docs/voice_ip_comm/pgw/9/provisioning/guide/R9MMLCfg.html

Provisioning Examples

As described before, there are no additional provisioning requirements associated with NBT or NCT. This section provides a provisioning example for iTNT on SIP trunks. Provisioning for TNT is similar to the provisioning of iTNT. However, the route list provisioned for TNT must be a real route list, whereas the route list provisioned for iTNT can be any existing route list. This difference is also pointed out in the following example.

Additional provisioning examples for the Cisco MGC software can be found in the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.

; Overdecadic Dial Plan for the mid-call service
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
numan-add:dialplan:custgrpid="2222",overdec="yes"
________________________________________
; Support Mid-call Service
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
prov-add:sigsvcprop:name="sipsvc1",MidCallServiceCustID="2222"
________________________________________
; Result Set
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
numan-add:resultset:custgrpid="2222",name="rset-itnt"
________________________________________
; Result Table
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
numan-add:resulttable:custgrpid="2222",name="digit-len",resulttype="DIGIT_REQ",
setname="rset-itnt",dw1="7"
;The total length of digits is 7 (including the length of the string "*8") for intelligent 
blind transfer service.

numan-add:resulttable:custgrpid="2222",name="itnt-bmod",resulttype="BMODDIG",dw1="1",
dw2="2",setname="rset-itnt"

numan-add:resulttable:custgrpid="2222",name="itnt-rte",resulttype="ROUTE",dw1="rtlist99",
setname="rset-itnt"
; Note: for TNT, a real route list name is required in the above command; for iTNT, you 
can enter any existing route list name in the above command.
________________________________________
; Digit String
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
numan-add:bdigtree:custgrpid="2222",callside="originating",digitstring="B82",
setname="rset-itnt"
;The digit string "*82xxxx" invokes the mid-call service and transfers the call. The 
string "*8" is removed from the digits after the digit analysis.
________________________________________
; Result Set
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
numan-add:resultset:custgrpid="2222",name="rset-err"
________________________________________
; Result Table
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
numan-add:resulttable:custgrpid="2222",name="max-len",resulttype="INC_NUMBERING",
setname="rset-err",dw1="0",dw2="2",dw3="2"
;The result type INC_NUMBERING is used to return an announcement immediately.

numan-add:resulttable:custgrpid="2222",name="itnt-ann",resulttype="ANNOUNCEMENT",
setname="rset-err",dw1="33",dw2="0",dw4="2"
;Note: for the mid-call announcement, the dw2 must be 0 and dw4 must be 2 (local and final 
announcement). This announcement is played to the transferring party if the digit string 
is matched.
________________________________________
; Digit String
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
numan-add:bdigtree:custgrpid="2222",callside="originating",digitstring="B9",
setname="rset-err"
;The string "*9" is not a valid transferred-to number prefix. The provisioned announcement 
is played when "*9" is dialed.
________________________________________
;Announcement ID in the TimesTen database announcement table
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
numan-add:announcement:annId=33,gwtype="AS5350",locationstring="ann_id_22.au",
playduration=10,repeat=1,interval=20

prov-cpy

Software Changes for This Feature

The following section contains software changes related to this feature:

Properties

Properties

The property identified in this section is used for the SIP Support of Take Back and Transfer in the Cisco Unified Contact Center feature. For information on other properties of the Cisco MGC software, see the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.

Table 1 identifies the property used for the SIP Support of Take Back and Transfer in the Cisco Unified Contact Center feature.

Table 1 Software Property Related to the Feature

Property Name
Parent Object
AVM
DPNSS
EISUP
IOCC
ISDNPRI
MGCP
RLM
SESSION
SGCP
SIP
SS7-ANSI
SS7-China
SS7-ITU
SS7-Japan
SS7-UK
TALI-IOCC
TCAPOverIP
TrunkGroup
VSI

MidCallServiceCustID

 

 X

 

 

 X

 

 

 

 

 X

 X

 

 X

 

 

 

 

 

 


Table 2 identifies the property used for the SIP Support of Take Back and Transfer in the Cisco Unified Contact Center feature.

Table 2 Property Used for the SIP Support of Take Back and Transfer in the Cisco Unified Contact Center 

Property
Definition

MidCallServiceCustID

A customer ID associated with mid-call service


Troubleshooting the Feature

The following section contains the procedures required for troubleshooting this feature.

If the iTNT or TNT doesn't work, use the following steps to do the troubleshooting:

 
Action
Description

Step 1 

Check if digits pressed during the call are correctly received on PGW.

1. Check if MGCP messages for transmitting DTMF digits pressed during the call are correctly received on PGW.

2. Check if the trunk group property UnsolicitedNotifyMethod is set to 1 when the transferring party is connected to Cisco Call Manager SIP trunk.

3. Check if the DTMF configuration on the gateway is correct.

Step 2 

Check if the MidCallServiceCustID property is configured correctly.

For more information on the definition of this property, see the Cisco Media Gateway Controller Software Release 9 Provisioning Guide at
http://www.cisco.com/en/US/docs/voice_ip_comm/pgw/9/provisioning/guide/prvgde.html

For the recommended provisioning, see the "Provisioning Examples" section.

Step 3 

(For iTNT only) Check if the ICM configuration is correct.

See the ICM user document for more information.

If the NBT or NCT doesn't work, use the following steps to do the troubleshooting.

 
Action
Description

Step 1 

Check if INAP connection between the PGW and the ICM is active.

Use the following MML commands to check the INAP connection between the PGW and the ICM,

rtrv-lssn:all
rtrv-rssn:all

Step 2 

Check the ICM configuration.

See the ICM user document for more information.

For more information on troubleshooting tasks for the rest of the Cisco MGC software, see the Cisco Media Gateway Controller Software Release 9 Operations, Maintenance, and Troubleshooting Guide at,

http://www.cisco.com/en/US/docs/voice_ip_comm/pgw/9/maintenance/guide/omtguide.html

If you still have problems with this feature, get the MDL trace and contact Cisco TAC.

Obtaining Documentation, Obtaining Support, and Security Guidelines

For information on obtaining documentation, obtaining support, providing documentation feedback, security guidelines, and also recommended aliases and general Cisco documents, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at

http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html

Glossary

Table 3 contains expansions of acronyms and technical terms used in this feature module.

Table 3 Acronyms and Expansions 

Acronym
Expansion

DTMF

dual-tone multifrequency

ICM

(Cisco) Unified Intelligent Contact Management

INAP

Intelligent Network Application Part

iTNT

intelligent blind transfer (DTMF blind transfer under INAP control)

MGC

(Cisco) Media Gateway Controller

MML

Man-Machine Language

NBT

network blind transfer

NCT

network consultation transfer

PGW

PSTN gateway

PRI

Primary Rate Interface

PSTN

public switched telephone network

SCP

service control point

Unified CCE

(Cisco) Unified Contact Center Enterprise, also known as (Cisco) IP Contact Center

SIP

Session Initiation Protocol

TCAP

Transaction Capability Application Protocol

TNT

take back and transfer