Conferencing

The CUCM supports hardware and software conference bridges.

The software-based conference bridge, implemented as a CUCM service, supports only conferences, using a single audio codec (G.711 or Cisco wideband).

Some hardware conference bridges can support multiple low bit-rate (LBR) stream types such as G.729, Global System for Mobile Communications (GSM), G.723, and iLBC. A mixed-mode conference is a conference in which multiple audio codecs are used for different audio streams. A mixed-mode conference bridge has the added burden of transcoding the RTP bearer streams. Mixed-mode conferences limit the number of conference participants and active conferences based on the capabilities of the hardware. There are multiple hardware conference bridge families that should be investigated.

NOTE Hardware conference capabilities are well documented in the CUCM Solution Reference Network Design Guide available at http://www.cisco.com/go/srnd. The DSP Calculator should also be used when designing a solution involving hardware media resources. As mentioned previously, the DSP Calculator is available at http:// www.cisco.com/go/dspcalculator.

Software conferencing scalability is limited by the server platform CUCM is running on. Conferencing capabilities of the server are throttled by default because it is assumed that CUCM will be running call processing co-resident while providing conferencing capabilities. The number of streams can be tuned up to 64 ad hoc conference participants and 128 meet-me conference participants on a standalone server (dependent on the server hardware platform). A standalone server is dedicated to providing services to the CUCM, but it never performs call processing (call setup and teardown).

A hardware conference bridge can support multiple LBR audio stream types, including G.729, GSM, G.723, and iLBC.

All conference bridges that are under the control of CUCM currently use SCCP to communicate with CUCM.

CUCM allocates a conference bridge from a conferencing resource that is registered with the CUCM cluster. Both hardware and software conferencing resources can register with CUCM at the same time, and CUCM can allocate conference bridges from either resource. CUCM does not distinguish between these types of conference bridges when it processes conference allocation requests.

The number of individual conferences and maximum number of participants per conference varies by resource.

Cisco Conference Bridge Hardware

The following types of hardware conference bridge resources may be used on a CUCM system:

Cisco Conference Bridge Hardware (Cisco Catalyst WS-X6608-T1 and WS-X6608-E1)

■ Cisco IOS Conference Bridge (Cisco NM-HDV)

■ Cisco Conference Bridge (Cisco WS-SVC-CMM and WS-SVC-CMM-ACT)

■ Cisco IOS Enhanced Conference Bridge (Cisco NM-HDV2, NM-HD-1V/2V/2VE, PVDM2)

■ Cisco Video Conference Bridge (CUVC-3510 or 3540)

Cisco Conference Bridge Hardware (Cisco Catalyst WS-X6608-T1 and WS-X6608-E1)

This hardware has eight DSPs that are physically associated to each port, and there are eight ports per card. The 6608 module is supported only in the Catalyst operating system of the 6500 series switch.

Configuration of the DSPs is at the port level, so all DSPs associated to a port perform the same function.

Conference bridges may have up to 32 participants, and each port supports 32 conference bridges.

For conferences with G.711 or G.723, there may be 32 conferences per port. If G.729 calls are used, there may be 24 conferences per port. The 6608-T1/E1 gateway module is end of sale (EoS).

Cisco IOS Conference Bridge (Cisco NM-HDV and 1700 Series Routers)

This hardware uses the PVDM-256K-type modules that are based on the C549 DSP chipset. Conferences using this hardware provide bridges that allow up to six participants in a single bridge.

The resources are configured per DSP for conference bridges.

The NM-HDV may have up to four PVDM-256K modules, whereas the Cisco 1700 series routers may have one or two PVDM-256K modules.

Each DSP provides a single conference bridge that can accept G.711 or G.729 calls.

The Cisco 1751 is limited to 5 conference calls per chassis, and the Cisco 1760 can support 20 conference calls per chassis.

Any PVDM2-based hardware, such as the NM-HDV2, may be used simultaneously in a single chassis for voice termination but may not be used simultaneously for other media resource functionality. The DSPs based on PVDM-256K and PVDM2 have different DSP farm configurations, and only one may be configured in a router at a time.

Cisco Conference Bridge (Cisco WS-SVC-CMM-ACT)

This Cisco Catalyst-based hardware provides DSP resources that may provide conference bridges of up to 32 participants per bridge.

Each module contains 4 DSPs that are individually configurable, and each DSP can support 32 conference bridges.

The G.711 and G.729 codecs are supported on these conference bridges without extra transcoder resources. However, transcoder resources are necessary if other codecs are used.

Cisco IOS Enhanced Conference Bridge (Cisco NM-HDV2, NM-HD-1V/2V/2VE, 2800 Series, and 3800 Series Routers)

Based on the Texas Instruments (TI) C5510 DSP chipset, the NM-HDV2 and the router chassis use the PVDM2 (Packet Voice DSP Modules - 2nd generation) modules for providing DSPs.

DSPs on PVDM2 hardware are configured individually as voice termination, conferencing, media termination, or transcoding resources. The DSPs on a single PVDM may be used as different resource types. Allocate DSPs to voice termination first, and then to other functionality as needed.

The NM-HDV2 (high-density voice) has four slots that will accept PVDM2 modules in any combination. The other network modules have fixed numbers of DSPs.

A conference based on these DSPs allows a maximum of eight participants. When a conference begins, all eight positions are reserved at that time. This means that unused DSP resources on the same DSP chip are not available for other conferences.

The PVDM2-8 is listed as having a DSP because it has a DSP that has half the processing capacity of the PVDM2-16. If the DSP on a PVDM2-8 is configured for G.711, it can provide (0.5 x 8) bridges/DSP = 4 conference bridges. PVDM2 modules are available in 8, 16, 32, 48, or 64 quantities. The number of resources uses a divisor of 16. A PVDM2-64 has 64/8, or 8 DSP resources, which will allow up to 64 conferences with 8 conference participants in each conference. The PVDM2 I/O limits the number of conference streams in this scenario because 512 (64 x 8) audio streams are possible with 64 conferences of 8 conference participants.

A DSP farm is a configuration parameter in Cisco IOS that specifies which codecs are supported for the DSPs that are working together (farming). A DSP farm that is configured for conferencing for G.711 provides 8 conferences. When configured to accept both G.711 and G.729 calls, a single DSP provides two conferences because it is also reserving its resources for performing transcoding of streams.

The I/O of an NM-HDV2 is limited to 400 streams, so ensure that the number of conference resources allocated does not cause this limit to be exceeded. If G.711 conferences are configured, no more than 6 DSPs (total of 48 conferences with 8 participants each) should be allocated per NM because 48 x 8 participants = 384 streams. If all conferencing is configured for both G.711 and G.729 codecs, each DSP provides only two conferences of eight participants each. In this case, it is possible to populate the network module (NM) fully and configure it with 16 DSPs (PVDM2-64) because there can only be 2 conferences with 8 participants (16) in each of the 16 DSPs (16 x 16 = 256 streams).

Conferences cannot natively accept calls using the GSM codec. A transcoder must be provided separately for these calls to participate in a conference.

Meet-me conferences allow users to dial in to a conference. Ad hoc conferences allow the conference controller to add specific participants to the conference.

Meet-me conferences require that a range of directory numbers (DN) be allocated for exclusive use of the conference. When a meet-me conference is set up, the conference controller chooses a DN and advertises it to members of the group. The users call the DN to join the conference after the conference controller has set up the bridge using the MeetMe softkey.

Ad hoc conferences comprise two types: basic and advanced. In basic ad hoc conferencing, the originator of the conference acts as the controller of the conference and is the only participant who can add or remove other participants.

In advanced ad hoc conferencing, any participant can add or remove other participants; that capability is not limited to the originator of the conference. Advanced ad hoc conferencing also allows linking multiple ad hoc conferences. Set the Advanced Ad Hoc Conference Enabled cluster-wide service parameter to True to gain access to advanced ad hoc conferencing. Advanced ad hoc conferencing is also referred to as conference chaining.

Conferencing Media Resource Configuration

The following steps are required to configure media resources:

1. Configure software conference media resources (if desired).

a. Enable the IP Voice Media Streaming application service.

b. Configure IP Voice Media Streaming application service parameters.

c. Configure desired software conferencing media resources.

2. Implement hardware conference media resources (if desired).

a. Configure hardware media resources in CUCM.

b. Configure hardware media resources in Cisco IOS.

c. Verify that hardware media resources are registered with CUCM.

The Cisco IP Voice Media Streaming application service is activated in Cisco Unified Serviceability at Tools > Service Activation. At the top of the Service Activation window, the server on which services should be activated or deactivated has to be selected. After selecting the server, check the IP Voice Media Streaming App check box (Figure 15-7) and click Save to activate the service.

The Cisco IPVMS parameters are accessible via the CUCM Administration, System > Service Parameters. The following two conference bridge service parameters are illustrated in Figure 15-8:

■ Call Count: This parameter specifies the maximum number of conference participants that the conference bridge will support. Increasing this value above the recommended default might cause performance degradation on a CUCM server that is also performing call processing (co-resident). If this value needs to be tuned above the default, consider installing the Cisco IPVMS on a standalone server. Alternatively, hardware conferencing or a version of Cisco MeetingPlace can be used to offload conferencing processing from the call-processing server. The configurable range is 0 to 256, and the default is 48.

■ Run Flag: This parameter determines whether the conference bridge functionality of the Cisco IPVMS is enabled. Valid values specify True (enabled) or False. The default is True. All media resources are turned on by default when the Cisco IPVMS is activated. Each media service can be turned on or off individually via the service parameters or MoH server configuration.

Figure 15-7 IP Voice Media Streaming Application Service Activation

Service Activation

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Figure 15-8 IP Voice Media Streaming Application Service Parameters

Figure 15-8 IP Voice Media Streaming Application Service Parameters

Moh Service Parameters

Figure 15-9 shows the default configuration of a software conference resource. The only configurable items are Name, Description, Device Pool, Common Device Configuration, and Location.

NOTE The CUCM software conferencing media resource supports only the G.711 and Cisco wideband audio codecs. A hardware conference bridge or transcoder is necessary to allow devices that use other audio codecs to participate in a conference.

Figure 15-9 IP Voice Media Streaming Application Service Parameters

Figure 15-9 IP Voice Media Streaming Application Service Parameters

Telephone Conference Bridge Schematic

When adding a hardware conference bridge in CUCM, the type of conference bridge must match the hardware family used. The IOS Enhanced Conference Bridge used in Figure 15-9 represents an NM-HDV2 or NM-HD-1V/2V/2VE, as discussed earlier in this chapter. This particular type of conference bridge is configured by name, which must match between CUCM and the Cisco IOS router.

To add a hardware conference bridge, navigate to Media Resources > Conference Bridge and click the Add New button. The Conference Bridge Configuration window displays. Enter the appropriate settings for that particular conference bridge and click Save. Figure 15-9 is based on a Cisco IOS Enhanced Conference Bridge configuration. Configurable parameters vary by platform.

■ Conference Bridge Type: Choose Cisco IOS Enhanced Conference Bridge.

■ Conference Bridge Name: Enter a name for the conference bridge. The name must match the name of the conference media resource as configured at the Cisco IOS router.

NOTE The name of the Cisco IOS Enhanced Conference Bridge configured in CUCM must match the name of the conference bridge configured in the Cisco IOS router. The name is case sensitive. Good naming conventions should be used to easily identify the component. Prefix CFB (conference bridge), and then use a burned-in MAC address of the router. CFB012345012345 is an example of a hardware conference bridge in a router where the MAC address of 012345012345 is burned into the Gigabit Ethernet controller.

■ Device Pool: Choose a device pool. Best practice is to configure a separate device pool dedicated to media resources. A good naming convention recommendation is Media_Resources_DP.

■ Common Device Configuration: Choose the common device configuration to assign to the conference bridge. The common device configuration includes attributes such as MoH audio source.

■ Location: Choose the appropriate location for this conference bridge to enforce call admission control (CAC). The location specifies the total bandwidth that is available for calls to and from this location. A location setting of Hub_None means that the Locations feature does not keep track of the bandwidth that this conference bridge consumes. CAC is covered in more detail in Cisco IP Telephony Part 2.

■ Device Security Mode: This field displays for Cisco IOS Enhanced Conference Bridge because only this audio conference bridge supports secure encrypted conferencing starting in CUCM Version 6.0. If choosing Non Secure Conference Bridge, the nonsecure conference establishes a TCP port connection to CUCM on port 2000. Ensure this setting matches the security setting on the conference bridge; otherwise, the call will fail. The Encrypted Conference Bridge setting supports the secure conference feature. Refer to the CUCM Security Guide for secure conference bridge configuration procedures.

Figure 15-10 Cisco IOS Enhanced Conference Bridge Configuration

Figure 15-10 Cisco IOS Enhanced Conference Bridge Configuration

Example 15-1 is a configuration of a Cisco IOS Enhanced Conference Bridge. Each command is explained following the configuration example.

Example 15-1 Cisco IOS Configuration voice-card 0 dspfarm dsp services dspfarm sccp local FastEthernet0/0.72

sccp ccm 10.1.1.1 identifier 1 version 6.0

sccp sccp ccm group 1 associate ccm 1 priority 1

associate profile 1 register CFB001B0CC250F8

dspfarm profile 1 conference codec g711ulaw codec g711alaw codec g729ar8 codec g729abr8 maximum sessions 2 associate application SCCP no shutdown

■ dspfarm (DSP farm): To enable DSP farm service, use the dspfarm command in global configuration mode. The DSP farm service is disabled by default.

■ dsp services dspfarm: To enable DSP farm services for a particular voice network module, use the dsp services dspfarm command.

■ sccp local: To select the local interface that SCCP applications (transcoding and conferencing) use to register with CUCM, use the sccp local command in global configuration mode.

■ sccp ccm: To add a CUCM server to the list of available servers and set various parameters, including IP address or DNS name, port number, and version number, use the sccp ccm command in global configuration mode.

■ sccp: To enable the SCCP protocol and its related applications (transcoding and conferencing), use the sccp command in global configuration mode.

■ sccp ccm group: To create a CUCM group and enter SCCP CUCM configuration mode, use the sccp ccm group command in global configuration mode.

■ associate ccm: To associate a CUCM with a CUCM group and establish its priority within the group, use the associate ccm command in SCCP CUCM configuration mode.

■ associate profile: To associate a DSP farm profile with a CUCM group, use the associate profile command in SCCP CUCM configuration mode.

■ dspfarm profile: To enter DSP farm profile configuration mode and define a profile for DSP farm services, use the dspfarm profile command in global configuration mode.

■ codec (DSP): To specify call density and codec complexity based on a particular codec standard, use the codec command in DSP interface DSP farm configuration mode.

■ associate application sccp: To associate SCCP to the DSP farm profile, use the associate application sccp command in DSP farm profile configuration mode.

■ maximum sessions (DSP farm profile): To specify the maximum number of sessions that are supported by the profile, use the maximum sessions command in DSP farm profile configuration mode.

■ no shutdown: If you fail to use the no shutdown command, the DSP farm profile will display in the gateway but fail to operate.

To verify the Cisco IOS media resource configuration, use the show commands demonstrated in Example 15-2.

Example 15-2 Verifying Cisco IOS Media Resource Configuration show sccp

SCCP Admin State: UP

Gateway IP Address: 10.1.1.101, Port Number: 2000

IP Precedence: 5

User Masked Codec list: None

Call Manager: 10.1.1.1, Port Number: 2000

Priority: N/A, Version: 6.0, Identifier: 1 Conferencing Oper State: ACTIVE - Cause Code: NONE Active Call Manager: 10.1.1.1, Port Number: 2000 TCP Link Status: CONNECTED, Profile Identifier: 1 Reported Max Streams: 16, Reported Max OOS Streams: 0 Supported Codec: g711ulaw, Maximum Packetization Period: 30 Supported Codec: g711alaw, Maximum Packetization Period: 30 Supported Codec: g729ar8, Maximum Packetization Period: 60 Supported Codec: g729abr8, Maximum Packetization Period: 60 Supported Codec: g729r8, Maximum Packetization Period: 60 Supported Codec: g729br8, Maximum Packetization Period: 60 Supported Codec: rfc2833 dtmf, Maximum Packetization Period: 30 Supported Codec: rfc2833 pass-thru, Maximum Packetization Period: 30 Supported Codec: inband-dtmf to rfc2833 conversion, Maximum Packetization Period: 30

Example 15-2 Verifying Cisco IOS Media Resource Configuration (Continued)

show sccp ccm group 1 CCM Group Identifier: 1 Description: None

Binded Interface: NONE, IP Address: NONE Associated CCM Id: 1, Priority in this CCM Group: 1

Associated Profile: 1, Registration Name: CFB001B0CC250F8

Registration Retries: 3, Registration Timeout: 10 sec Keepalive Retries: 3, Keepalive Timeout: 30 sec CCM Connect Retries: 3, CCM Connect Interval: 10 sec Switchover Method: GRACEFUL,Switchback Method: GRACEFUL_GUARD Switchback Interval: 10 sec, Switchback Timeout: 7200 sec Signaling DSCP value: cs3, Audio DSCP value: ef show dspfarm profile 1

Dspfarm Profile Configuration Profile ID = 1, Service = CONFERENCING, Resource ID = 1 Profile Description : Profile Admin State : UP Profile Operation State : ACTIVE Application : SCCP Status : ASSOCIATED Resource Provider : FLEX_DSPRM Status : UP

Number of Resource Configured : 2 Number of Resource Available : 2

Codec Configuration

Codec : g711ulaw, Maximum Packetization Period : 30 , Transcoder: Not Required

Codec : g711alaw, Maximum Packetization Period : 30 , Transcoder: Not Required

Codec : g729ar8, Maximum Packetization Period : 60 , Transcoder: Not Required

Codec : g729abr8, Maximum Packetization Period : 60 , Transcoder: Not Required

Codec : g729r8, Maximum Packetization Period : 60 , Transcoder: Not Required

Codec : g729br8, Maximum Packetization Period : 60 , Transcoder: Not Required

Various CUCM service parameters are related to conferencing. The following conferencing options should be considered when leveraging the conferencing features of CUCM:

■ Suppress Music on Hold to Conference Bridge: This parameter determines whether MoH plays to a conference when a conference participant places the conference on hold. Valid values specify True (the system does not play MoH to the conference when a conference participant presses the Hold button) or False. The default is True.

■ Drop Ad Hoc Conference: This parameter determines how an ad hoc conference terminates. This is an important toll-fraud prevention setting, because inside facilitators can set up a conference call to expensive international numbers and then drop out of the call. Without the conference controller, international tariffs are billed back to the company in which the conference call was set up. Valid values are as follows:

—Never (default): The conference remains active after the conference controller and all on-net parties hang up. This default setting could result in potential toll fraud.

—When Conference Controller Leaves: Terminate the conference when the conference controller hangs up.

—When No On-Net Parties Remain in the Conference: Terminate the conference when there are no on-net parties remaining in the conference. This distinction is important because the conference controller might have to drop out of the call, but other business partners on the call should continue the conference. The When Conference Controller Leaves option would hang up the call when the conference controller left the conference.

■ Advanced Ad Hoc Conference Enabled: This parameter determines whether advanced ad hoc conference features are enabled. Advanced ad hoc conference features include the ability for conference participants other than the conference controller to add new participants to an existing ad hoc conference (conference chaining); the ability for any noncontroller conference participant to drop other participants from the conference via the ConfList and RmLstC softkeys; and whether ad hoc conferences can be linked using features such as conference, join, direct transfer, and transfer. Valid values specify True (allow advanced ad hoc conference features) or False. The default is False.

■ Nonlinear Ad Hoc Conference Linking Enabled: This parameter determines whether more than two ad hoc conferences can be linked directly to an ad hoc conference in a nonlinear fashion. Nonlinear conference linking occurs when three or more ad hoc conferences are linked directly to one other ad hoc conference. Linear conference linking occurs when one or two ad hoc conferences are linked directly to one other ad hoc conference. For this parameter to work, the Advanced Ad Hoc Conference Enabled service parameter must be set to True. Valid values specify True (allow nonlinear conference linking so that three or more ad hoc conferences can be linked to a single other conference) or False. The default is False. The Advanced Ad Hoc Conference Enabled service parameter must be set to True for the Nonlinear Ad Hoc Conference Linking Enabled service parameter to work.

■ Maximum Ad Hoc Conference: This parameter specifies the maximum number of participants who are allowed in a single ad hoc conference. The value of this field depends on the capabilities of the software/hardware conference bridge. The maximum number of conference bridge participants for typical conference bridges follow:

Software, 64; Cisco Catalyst WS-X6608, 16; Cisco Catalyst 4000, 16; and NM-HDV, 6. Setting this value above the maximum capacity of the conference resource will result in failed entrance to a conference bridge if more ports than the specific conference bridge configuration allows are added. The range is 3 to 64. The default is 4.

■ Maximum Meet-Me Conference Unicast: This parameter specifies the maximum number of participants that are allowed in a single meet-me conference. The value of this field depends on the capabilities of the software/hardware conference bridge. A software conference bridge is capable of conferencing up to 128 participants. When a conference is created, the system automatically reserves a minimum of three streams, so specifying a value less than 3 allows a maximum of three participants. The range is 1 to 128. The default is 4.

Meet-Me Conference Configuration

To add a range of numbers to be used for meet-me conferences in CUCM Administration, navigate to Call Routing > Meet-Me Number/Pattern and click Add New. Configure the new pattern with the following data:

■ Directory Number or Pattern: Enter a meet-me number or number range.

■ Description: Enter up to 30 alphanumeric characters for a description of the meet-me number.

■ Partition: To use a partition to restrict access to the meet-me/number pattern, choose the desired partition from the drop-down list.

■ Minimum Security Level: Choose the minimum meet-me conference security level for this meet-me number or pattern from the drop-down list:

—Choose Authenticated to block participants with nonsecure phones from joining the conference.

—Choose Encrypted to block participants with authenticated or nonsecure phones from joining the conference.

—Choose Non Secure to allow all participants to join the conference.

Figure 15-11 shows a meet-me range of 100 numbers beginning with 4500 and ending with 4599. The numbers are not in a partition, which will allow any phone to set up a meet-me bridge by clicking the Meet-Me softkey and dialing one of the numbers in the meet-me number range. Subsequent meeting members will need to dial only the number of the bridge.

Figure 15-11 Meet-Me Conference Bridge Configuration

Figure 15-11 Meet-Me Conference Bridge Configuration

NOTE Meet-me bridges do not offer any security, scheduling, or name-confirmation features. Security and scheduling features are offered by the Cisco MeetingPlace and Cisco MeetingPlace Express products. The conference controller could be given access to the ConfList softkey, which will allow the controller to view the conference participants by caller ID information. The conference controller can individually remove users, but the conference controller does not have access to the users' line state information. Cisco MeetingPlace and MeetingPlace Express allow the conference controller to see which conference participant has a phone on hold. This is especially useful if MoH is being injected into the conference bridge. If the bridge has not been set up by the controller, callers to the meet-me number pattern receive a reorder tone.

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