Page tree
Skip to end of metadata
Go to start of metadata

Table of Contents


Document Overview

This document is a configuration guide for the Sonus SBC 2000 (Session Border Controller) when connecting to Skype for Business 2015 (Skype 2015) and SwissCom SIP Trunk.

This configuration guide supports features provided in the Microsoft Technet web page.


The interoperability compliance testing focuses on verifying various inbound and outbound call flows between Sonus SBC 2000 and Skype 2015.


This technical document is intended for telecommunication engineers with the purpose of configuring the Sonus SBC 2000 aspects of the SwissCom SIP trunk group together with Skype 2015. Some steps will require navigating third-party equipment and Sonus SBC Web browser user interfaces. Understanding IP/Routing and SIP/RTP basic concepts are also necessary to complete the configuration and perform any troubleshooting, if necessary.


This configuration guide is offered as a convenience to Sonus customers. The specifications and information regarding the product in this guide are subject to change without notice. All statements, information, and recommendations in this guide are believed to be accurate but are presented without warranty of any kind, express or implied, and are provided “AS IS”. Users must take full responsibility for the application of the specifications and information in this guide.


The following equipment and software were used for the provided sample configuration:

Table : Requirements

Sonus NetworksSBC 2000 V5.0.3build407
Tenor AF P108-09-21
Third-Party EquipmentMicrosoft Skype for Business 2015 (Skype 2015) Mediation Server 6.0.9319.0

Polycom CX600 SIP Phone


Reference Configuration

The following reference configuration shows connectivity between third-party equipment and Sonus SBC 2000.

Figure : Connectivity Between Third-Party and Sonus SBC 2000



Technical support for Sonus SBC 2000 series is available via phone or logging a trouble ticket:

Third-Party Product Features

The following features were tested using the SwissCom test plan:

  • Basic originated and terminated calls
  • Basic inbound/outbound call
  • Hold and Resume
  • Call Forwarding Unconditional
  • FAX
  • DTMF 

Verify License

No special licensing required.


Skype 2015 Configuration

The following new configurations are included in this section:

  1. PSTN Gateway
  2. Voice Policy
  3. PSTN Usage
  4. Route
  5. Trunk Configuration
  6. Dial Plan

1. PSTN Gateway

To configure the PSTN Gateway, select Topology Builder > Shared Components > PSTN Gateways, as shown in the following figures.

Figure : Define a new IP/PSTN Gateway

Figure : Define FQDN

Figure : Define IP Address

Figure : Define Root Trunk

2. Voice Policy

To configure Voice Policy, select Control Panel > Voice Routing > Voice Policy, as shown in the following figure.

Figure : Edit Voice Policy

3. PSTN Usage

To configure the PSTN Usage, select Control Panel > Voice Routing > PSTN Usage, as shown in the following figure.

Figure : View PSTN Usage

4. Route

To configure Route, select Control Panel > Voice Routing > Route, as shown in the following figures.

Figure : Edit Voice Route



Figure : Edit Voice Route 2



5. Trunk Configuration

To configure the Trunk, select Control Panel > Voice Routing > Trunk Configuration, as shown in the following figure.

Figure : Edit Trunk Configuration


6. Dial Plan

To configure the Dial Plan, select Control Panel > Voice Routing > Dial Plan > Normalization rules, as shown in the following figure.

Figure : Dial Plan Configuration

Sonus SBC 2000 Configuration

The following steps provide an example of how to configure Sonus SBC 2000.

  1. SIP Profile
  2. SIP Server
  3. Media Profile
  4. Media Lists
  5. Message Manipulation
  6. Signaling Groups
  7. Transformation
  8. Call Routing Table

1. SIP Profile

SIP Profiles control how the Sonus SBC 2000 communicates with SIP devices. These control important characteristics such as: session timers, SIP Header customization, SIP timers, MIME payloads, and option tags.

To configure the SIP Profile, select Settings > SIP > SIP Profiles.

For this test effort, the default SIP profile used for the SBC 2000 is shown in the following figures.

Figure : SwissCom SIP Profile

Figure : Skype 2015 SIP Profile



Figure : Fax SIP Profile


2. SIP Server 

SIP Server tables contain information about the SIP devices connected to the Sonus SBC 2000. The table entries provide information about the IP addresses, ports, and protocols used to communicate with each SIP server. The entries also contain links to counters that are useful for troubleshooting.

To configure the SIP Server, select Settings > SIP > SIP Server Tables, as shown in the following figures.

Figure : SwissCom SIP Server


Figure : Skype 2015 SIP Server


Figure : Fax SIP Server


3. Media Profile

Media profiles specify the individual voice and fax compression codecs and their associated settings for inclusion into a Media list. Different codecs provide varying levels of compression, allowing the reduction of bandwidth requirements at the expense of voice quality. 

To access the Media Profile, select Settings > Media > Media Profiles.

For this test effort, the following figures show the media profiles of the voice codecs used for the SBC 2000 and are provided for reference only.

Figure : SwissCom Voice Codec Media Profiles

Figure : Skype 2015 Voice Codec Media Profiles

Figure : Fax Voice Codec Media Profiles

4. Media Lists

The Media list shows the selected voice and fax compression codecs and their associated settings.

To access Media lists, select Settings > Media > Media List, as shown in the following figures.

Figure : SwissCom Media Lists

Figure : Skype 2015 Media Lists

Figure : Fax Media Lists

5. Message Manipulation

Condition rules are simple rules that apply to a specific component of a message (for example,,, etc.) and the value of the field specified in the Match Type list box is matched against a literal value, token, or REGEX.

To configure Message Manipulation, select Settings > SIP > Message Manipulation > Condition Rule Table, as shown in the following figures.

Figure : Condition Rule ID 2

Figure : Condition Rule ID 3

Figure : Condition Rule ID 5

Figure : Skype 2015 Add PAID Header

Figure : Skype 2015 Add Privacy Header

Figure : Skype 2015 PAID Host Part

Figure : SwissCom Delete Allow Header

Figure : SwissCom Add Allow Header

Figure : SwissCom Anonymous From Header

Figure : SwissCom Anonymous Contact Header

Figure : SwissCom PAID Header from Diversion Header

Figure : SwissCom Inactive To SendOnly manipulation

6. Signaling Groups

Signaling Groups allow telephony channels to be grouped together for the purposes of routing and shared configuration. These groups are the entity to which calls are routed, as well as the location from which Call Routes are selected. Signaling Groups are also the locations from which Tone Tables and Action Sets are selected. In the case of SIP, this will specify protocol settings and link to server, media, and mapping tables.

To configure Signaling Groups, select Settings > Signaling Groups, as shown in the following figures.

Figure : SwissCom Signaling Group


Figure : Skype 2015 Signaling Group


Figure : Fax Signaling Group


7. Transformation

Transformation tables facilitate the conversion of names, numbers and other fields when routing a call. For example, transformations convert a public PSTN number into a private extension number or a SIP address (URI). Every entry in a Call Routing table requires a Transformation table, which are sequentially selected. In addition, Transformation tables are configurable as a reusable pool that Action Sets can reference.

To configure the Transformation table, select Settings > Transformation, as shown in the figures below.

Figure : Transformation Tables Example

Figure : Fax Tables Example

8. Call Routing Table

Call Routing allows calls to be carried between Signaling Groups, thus allowing calls to be carried between ports and between protocols (for example, ISDN to SIP). Routes are defined by Call Routing tables, which allows for flexible configuration of calls that are carried, as well as how the calls are translated. These tables are one of the central connection points of the system linking Transformation tables, Message translations, Cause Code Reroutes, Media lists, and the three types of Signaling Groups: ISDN, SIP, and CAS.

To configure the Call Routing Table, select Settings > Call Routing Table, as shown in the following figures.


Figure : SwissCom Call Routing Table

Figure : Skype 2015 Call Routing Table

Figure : Fax Call Routing Table

Interoperability Test Results

The following table provides results from interoperability compliance testing.

Table : Test Results

SourceIdentityTelephone NumbertoTargetTelephone NumberTest ResultComments
Outgoing call       
Sonus/IPPBXBa-000000313034580to PSTN FX0313116924Pass 
Sonus/IPPBXBa-000010313034580to Lync20130614049795Pass 
Sonus/IPPBXBa-000020313034580to CICM Phone0614049711Pass 
Sonus/IPPBXBa-000030313034580to Mediatrix0614049936Pass 
Sonus/IPPBXBa-000040313034580to Natel oCMN0797463043Pass 
Sonus/IPPBXBa-000050313034580to SIP PBX0614049831Pass 
Sonus/IPPBXBa-000060313034580to IN 0800800103Pass 
Sonus/IPPBXBa-000070313034580to Short Nb161Pass 
Sonus/IPPBXMe-000000313034580to Mediant0614049971Pass 
CLIR Outgoing call       
Sonus/IPPBXBa-000080313034581to PSTN FX0313116924Pass 
Sonus/IPPBXBa-000090313034581to Lync20130614049795Pass 
Sonus/IPPBXBa-000100313034581to CICM Phone0614049711Pass 
Sonus/IPPBXBa-000110313034581to Mediatrix0614049936Pass 
Sonus/IPPBXBa-000120313034581to SIP PBX0614049831Pass 
Sonus/IPPBXMe-000010313034581to Mediant0614049971Pass 
Incoming call       
PSTN FXBa-000130313116924to Sonus/IPPBX0313034580Pass 
Lync2013Ba-000140614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000150614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-000160614049936to Sonus/IPPBX0-0313034580Pass 
MobileBa-000170797463043to Sonus/IPPBX0313034580Pass 
SIP PBXBa-000180614049831to Sonus/IPPBX65-0313034580Pass 
MediantMe-000020614049971to Sonus/IPPBX0313034580Pass 
Outgoing call unknown number       
Sonus/IPPBXBa-000190313034580to PSTN071 111 1111Pass 
Outgoing call mobile (mobil not reachable)       
Sonus/IPPBXBa-000200313034580to PSTN079 746 30 43Pass 
Call hold / resume (with music on hold; hold is done on PBX)       
PSTN FIXBa-000210313116924to Sonus/IPPBX0313034580Pass 
Lync2013Ba-000220614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000230614049711to Sonus/IPPBX0313034580Pass 
MediatrixBa-000240614049936to Sonus/IPPBX0313034580Pass 
MobileBa-000250797463043to Sonus/IPPBX0313034580Pass 
SIP PBXBa-000260614049831to Sonus/IPPBX0313034580Pass 
MediantMe-000030614049971to Sonus/IPPBX0313034580Pass 
Call hold / resume (with music on hold; hold is done on PBX)       
Sonus/IPPBXBa-000270313034580to PSTN FIX0313116924Pass 
Sonus/IPPBXBa-000280313034580to Lync20130614049795Pass 
Sonus/IPPBXBa-000290313034580to CICM Phone0614049711Pass 
Sonus/IPPBXBa-000300313034580to Mediatrix0614049936Pass 
Sonus/IPPBXBa-000310313034580to Mobile0797463043Pass 
Sonus/IPPBXBa-000320313034580to SIP PBX0614049831Pass 
Sonus/IPPBXMe-000040313034580to Mediant0614049971Pass 
Call hold / resume (without music on hold; hold is done on PBX)       
PSTN FIXBa-000330313116924to Sonus/IPPBX0313034580Not Applicable 
Lync2010 Ba-000340614049795to Sonus/IPPBX0-0313034580Not Applicable 
CICM PhoneBa-000350614049711to Sonus/IPPBX0-0313034580Not Applicable 
MediatrixBa-000360614049930to Sonus/IPPBX0-0313034580Not Applicable 
MobileBa-000370797463043to Sonus/IPPBX0313034580Not Applicable 
SIP PBXBa-000380614049831to Sonus/IPPBX65-0313034580Not Applicable 
MediantMe-000050614049971to Sonus/IPPBX0313034580Not Applicable 
Call hold / resume (without music on hold; hold is done on PBX)       
Sonus/IPPBXBa-000390313034580to PSTN FIX0313116924Not Applicable 
Sonus/IPPBXBa-000400313034580to Lync20100614049795Not Applicable 
Sonus/IPPBXBa-000410313034580to CICM Phone0614049711Not Applicable 
Sonus/IPPBXBa-000420313034580to Mediatrix0614049936Not Applicable 
Sonus/IPPBXBa-000430313034580to Mobile0797463043Not Applicable 
Sonus/IPPBXBa-000440313034580to SIP PBX0614049831Not Applicable 
Sonus/IPPBXMe-000060313034580to Mediant0614049971Not Applicable 
Call transfer internal (with person to person call)       
PSTN FIXBa-000450313116924to Sonus/IPPBX0313034580Pass 
Lync2010 Ba-000460614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000470614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-000480614049936to Sonus/IPPBX0-0313034580Pass 
MobileBa-000490797463043to Sonus/IPPBX0313034580Deferred 
SIP PBXBa-000500614049831to Sonus/IPPBX65-0313034580Pass 
MediantMe-000070614049971to Sonus/IPPBX0313034580Pass 
Call transfer internal ( BLIND without advance notification)       
PSTN FIXBa-000510313116924to Sonus/IPPBX0313034580Pass 
LyncBa-000520614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000530614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-000540614049936to Sonus/IPPBX0-0313034580Pass 
MobileBa-000550797463043to Sonus/IPPBX0313034580Deferred 
SIP PBXBa-000560614049831to Sonus/IPPBX65-0313034580Pass 
MediantMe-000080614049971to Sonus/IPPBX0313034580Pass 
Call transfer external (with advance notification)       
PSTN FIXBa-000570313116924to Sonus/IPPBX0313034580Pass 
Lync 2013Ba-000580614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000590614049711to Sonus/IPPBX0313034580Pass 
MediatrixBa-000600614049936to Sonus/IPPBX0313034580Pass 
MobileBa-000610797463043to Sonus/IPPBX0313034580Deferred 
SIP PBXBa-000620614049831to Sonus/IPPBX0313034580Pass 
MediantMe-000090614049971to Sonus/IPPBX0313034580Pass 
Call transfer external (without notification)       
PSTN FIXBa-000630313116924to Sonus/IPPBX0313034580Pass 
Lync 2013Ba-000640614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000650614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-000660614049930to Sonus/IPPBX0-0313034580Pass 
MobileBa-000670797463043to Sonus/IPPBX0313034580Pass 
SIP PBXBa-000680614049831to Sonus/IPPBX65-0313034580Pass 
MediantMe-000100614049971to Sonus/IPPBX0313034580Pass 
Call forward internal       
PSTN FIXBa-000690313116924to Sonus/IPPBX0313034580Pass 
Lync2010Ba-000700614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000710614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-000720614049936to Sonus/IPPBX0-0313034580Pass 
MobileBa-000730797463043to Sonus/IPPBX0313034580Deferred 
SIP PBXBa-000740614049831to Sonus/IPPBX65-0313034580Pass 
MediantMe-000110614049971to Sonus/IPPBX0313034580Pass 
Call forward external       
PSTN FIXBa-000750313116924to Sonus/IPPBX0313034580Pass 
PSTN FIXBa-000760313116924to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000770614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-000780614049936to Sonus/IPPBX0-0313034580Pass 
MobileBa-000790797463043to Sonus/IPPBX0313034580Pass 
SIP PBXBa-000800614049831to Sonus/IPPBX65-0313034580Pass 
MediantMe-000120614049971to Sonus/IPPBX0313034580Pass 
Conference 2 x internal 1 x external       
PSTN FIXBa-000810313116924to Sonus/IPPBX0313034580Pass 
Lync2010 Ba-000820614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000830614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-000840614049936to Sonus/IPPBX0-0313034580Deferred 
MobileBa-000850797463043to Sonus/IPPBX0313034580Deferred 
SIP PBXBa-000860614049831to Sonus/IPPBX65-0313034580Pass 
MediantMe-000130614049971to Sonus/IPPBX0313034580Pass 
Conference 1 x internal 2 x external       
PSTN FIXBa-000870313116924to Sonus/IPPBX0313034580Pass 
Lync2010Ba-000880614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-000890614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-000900614049936to Sonus/IPPBX0-0313034580Pass 
MobileBa-000910797463043to Sonus/IPPBX0313034580Pass 
SIP PBXBa-000920614049831to Sonus/IPPBX65-0313034580Pass 
MediantMe-000140614049971to Sonus/IPPBX0313034580Pass 
DTMF outgoing       
Sonus/IPPBXBa-000930313034580to PSTN FIX0800800103Pass 
Sonus/IPPBXBa-000940313034580to Lync0614049795Pass 
Sonus/IPPBXBa-000950313034580to CICM Phone0614049711Pass 
Sonus/IPPBXBa-000960313034580to Mediatrix0614049936Pass 
Sonus/IPPBXBa-000970313034580to Mobile0797463043Pass 
Sonus/IPPBXBa-000980313034580to SIP PBX0614049831Pass 
Sonus/IPPBXMe-000150313034580to Mediant0614049971Pass 
DTMF incoming       
PSTN FIXBa-000990313116924to Sonus/IPPBX0313034580Pass 
LyncBa-001000614049795to Sonus/IPPBX0313034580Pass 
CICM PhoneBa-001010614049711to Sonus/IPPBX0-0313034580Pass 
MediatrixBa-001020614049936to Sonus/IPPBX0-0313034580Pass 
MobileBa-001030797463043to Sonus/IPPBX0313034580Pass 
SIP PBXBa-00104614049855to Sonus/IPPBX65-0313034580Pass 
MediantMe-000160614049971to Sonus/IPPBX0313034580Pass 
FAX T.38 incoming       
PSTN FIXBa-001050313116925to Sonus/IPPBX0313034589Pass 
MediatrixBa-001060614049936to Sonus/IPPBX0313034589Pass 
KofaxBa-001070244229900to Sonus/IPPBX0313034589Deferred 
DialogicBa-001080614049871to Sonus/IPPBX0313034589Pass 
FAX T.38 outgoing       
Sonus/IPPBXBa-001090313034589to PSTN FIX0313116925Pass 
Sonus/IPPBXBa-001100313034589to Mediatrix0614049930Pass 
Sonus/IPPBXBa-001110313034589to Kofax0244229900Deferred 
Sonus/IPPBXEx-000010313034589to Dialogic0614049871Pass 
FAX Transparent incoming       
PSTN FIXBa-001120313116925to Sonus/IPPBX0313034589Open 
MediatrixBa-001130614049992to Sonus/IPPBX0313034589Open 
SIP PBXBa-001140614049839to Sonus/IPPBX0313034589Pass 
FAX Transparent outgoing       
Sonus/IPPBXBa-001150313034589to PSTN FIX0313116925Open 
Sonus/IPPBXBa-001160313034589to Mediatrix0614049992Pass 
Sonus/IPPBXBa-001170313034589to SIP PBX0614049839Pass 
Use cases       
SIP OPTIONBa-00118n/ato Sonus/IPPBXn/aPass 
SIP OPTIONBa-00119n/ato Sonus/IPPBXn/aPass 
SIP PBXBa-001200614049831to Sonus/IPPBX0313034580Pass 
Mobile/PSTNBa-00121CLIRto Sonus/IPPBX0313034580Pass 
SIP OPTIONBa-00122  SSL/A2 PassSee Ba-00118 for traces
Outgoing call MS       
Sonus/IPPBXAd-000000313034580to H.323 trunk
RAS less
Sonus/IPPBXAd-000010313034580to H.323 trunk
Sonus/IPPBXAd-000020313034580to SIP trunk
Cisco std.
Sonus/IPPBXAd-000030313034580to MCC Cisco0614049855Pass 
Incoming call MS     Pass 
H.323 trunk
RAS less
(with prefix 68)
to Sonus/IPPBX0313034580Pass 
H.323 trunk
(with prefix 60)
to Sonus/IPPBX0313034580Pass 
H.323 trunk
(with prefix *31)
to Sonus/IPPBX0313034580Pass 
SIP trunk
(with prefix 65)
to Sonus/IPPBX0313034580Pass 
SIP trunk
Cisco (CLIR)
(with prefix 64)
to Sonus/IPPBX0313034580Pass 
MCC CiscoAd-000090614049855
(with prefix 0)
to Sonus/IPPBX0313034580Pass 
Basic treatment       
Sonus/IPPBXAd-000100313034580to PSTN / CICMBusy numberPass 
PSTNAd-000110313116924to Sonus/IPPBXNb ot availablePassMust perform msg 404
Sonus/IPPBXAd-000120313034580to PSTN0313116924PassMust perform msg 603
Sonus/IPPBXAd-000130313034580to PSTN0313116924PassMust perform msg 503
Features interworking     Pass 
PSTNAd-000140313116924to Sonus/IPPBX0313034580Not Applicable 
PSTNAd-000150313116924to Sonus/IPPBX0313034580Pass 
Call forward external  to PSTN     Pass 
H.323 trunk
RAS less
Ad-00016061 404 97 21
(with prefix 68)
to Sonus/IPPBX0313034580Pass 
H.323 trunk
Ad-00017061 404 97 31
(with prefix 60)
to Sonus/IPPBX0313034580Pass 
Call hold / resume (with music on hold)       
H.323 trunk
RAS less
Ad-00042061 404 97 21
(with prefix 68)
to Sonus/IPPBX0313034580Pass 
H.323 trunk
Ad-00043061 404 97 31
(with prefix 60)
to Sonus/IPPBX0313034580Pass 
MCC CiscoAd-00044061 404 98 55to Sonus/IPPBX0313034580Pass 
Use case RTCP       
PSTNAd-000450313116924to Sonus/IPPBX0313034580Pass See below the next STEP
STEP 1 Sonus/IPPBX places the call on hold for more than 32 seconds     
STEP 2 Sonus/IPPBX sends RTCP packets while on hold    RTCP are sent from MS to PVG
STEP 3 Platform sends RTCP packets while on hold    RTCP are sent from PVG to MS
STEP 4 Sonus/IPPBX resumes the call     
STEP 5 Sonus/IPPBX hangs up    Call is disconnected
Use case Long Hold 1       
Sonus/IPPBXAd-000460313034580to PSTN0313116924PassSee below the next STEP
STEP 1 Sonus/IPPBX initiates call hold     
STEP 2 Wait for 12 minutes     
STEP 3 Sonus/IPPBX resumes the call    Bi-directional audio
STEP 4 Sonus/IPPBX hangs up    Call is disconnected
Use case Long Hold 2       
PSTNAd-000470313116924to Sonus/IPPBX0313034580PassSee below the next STEP
STEP 1 Sonus/IPPBX initiates call hold     
STEP 2 Wait for 15 minutes     
STEP 3 Sonus/IPPBX resumes the call    Bi-directional audio
STEP 4 Sonus/IPPBX hangs up    Call is disconnected
Use case Early Media       
PSTNAd-000480313116924to Sonus/IPPBX0313034580PassSee below the next STEP
       hears ring tone instead of ivr
STEP 1 Sonus/IPPBX rings     
STEP 2 PSTN is connected with the 2nd leg     
STEP 3 Sonus/IPPBX picks up the call ow    Cancel is sent to the 2nd leg
STEP 4 "interworking"    Platform returns msg 487
STEP 5 "voice"    Bi-directional audio established
STEP 6 Sonus/IPPBX hangs up    Call is disconnected
Use case Multiple Call Forward       
PSTNAd-000490313116924to Sonus/IPPBX0313034580Not ApplicableSee below the next STEP
STEP 1 Sonus/IPPBX rings     
STEP 2 PSTN is connected with the 2nd leg    PSTN is able to hear the IVR menu (mobile)
STEP 3 Sonus/IPPBX picks up the call ow    Cancel is sent to the 2nd leg
STEP 4 "interworking"    Platform returns msg 487
STEP 5 "voice"    Bi-directional audio established
STEP 6 Sonus/IPPBX hangs up    Call is disconnected
Call forward external - o EarlyM - with Mobile       
SIP trunk
Cisco (CLIR)
Ad-00050061 404 98 32
(with prefix 64)
to Sonus/IPPBX0313034580Pass 
Call forward No Answer external  to PSTN       
SIP trunk
Ad-00051061 404 98 31
(with prefix 65)
to Sonus/IPPBX0313034580Pass 
SIP trunk
Cisco (CLIR)
Ad-00052061 404 98 31
(with prefix 64)
to Sonus/IPPBX0313034580Pass 
MCC CiscoAd-00053061 404 98 55
(with prefix 0)
to Sonus/IPPBX0313034580Pass 
CICMAd-000540614049711to Sonus/IPPBX0313034580Pass 
Lync 2013Ad-000550614049795to Sonus/IPPBX0313034580Pass 
PSTN MobileAd-000560797463043to Sonus/IPPBX0313034580Pass 


Skype 2015 rejects SIP Re-Invite (usually hold method) from a caller side immediately after the first SIP ACK message is received (acknowledge for the first SIP Invite) with SIP 491 response. SBC follows RFC3261 and starts the random timer between 2.1 and 4 seconds after it tries to send SIP Re-Invite again. During the first 10 second time period, the Skype client is not able to put the caller on hold. The call itself is not affected as the connection is on a dual direction (both way) media. The Skype client can put the caller side on hold after this time period. This behaviour is found for some specific endpoints.


This Application Note describes the configuration steps required to enable the Sonus SBC 2000 to successfully interoperate with Skype for Business 2015. All feature and serviceability test cases were completed and passed with the exceptions/observations noted in section Interoperability Test Results.