Use of DSP resources for conferences with IP members

The "chat" command allows to create conference with multeple rooms. This allows to create conference between E.1/T.1/S0/Analog and IP members in fully transparent to user way. "chat" command always detects the type of connection and uses appropriate resources.

The implementation of "chat" for IP endpoints uses Diva NULL PLCI. While this resource is available for every Diva hardware and allows to create high amount of IP endpoints running parallel to E.1/T.1/S0/Analog endpoints on the same Diva hardware it does not allows access to DSP resources for IP conference members.

This is the reason why new "resource" command is added to chan_capi. This command allows to assign DSP resource to IP conference member. This is no need fo user to check the type of connection and the type of Diva hardware is using this command. The "resource" command detects automatically the type of connection and type of hardware and perform requested actions only if necessary and possible.

The other more general way to use DSP resources for IP connections is to use Diva softIP. In this case IP traffic is processed by Diva protocol stack and presented as E.1/T.1 interface to chan_capi. This is not IP connection from the point of view of chan_capi and no additional commands are required.

Example (from README.media):

[isdn-in]
exten => _X.,1,Answer     ; Answer the line
exten => _X.,n,Goto(s,1)
exten => s,1,capicommand(resource|1-4)           ; Create DSP resource on CAPI controllers 1-4 for IP members, ignore command for E.1/T.1/S0/POTS members
exten => s,n,capicommand(clamping|100)         ; Activate suppression of DTMF tones
exten => s,n,capicommand(rxagc|yes)            ; Activate Rx AGC
exten => s,n,capicommand(noisesuppressor|yes)  ; Activate suppression of ambient noises
exten => s,n,capicommand(vc|incrxdgain|0|1.5)  ; Install voice command menu for volume control, '0' to increase volume
exten => s,n,capicommand(vc|incrxdgain|1|-1.5) ; Install voice command menu for volume control, '1' to decrease volume
exten => s,n,capicommand(vc|txdgain|2|-128) ; Install voice command menu for volume control, '2' to mute tx path
exten => s,n,capicommand(vc|txdgain|3|0) ; Install voice command menu for volume control, '3' to activate tx path
exten => s,n,capicommand(chat|test1|m|1-4)     ; Craete/enter conference toom 'test1', controller field is ignored if media processing resource is assigned by 'resource' command or for E.1/T.1/S0/POTS members

Supported hardware (from README.media):

Supported hardware:
 Assign DSP resources to connected by IP network conference member. This feature is available
 for equipped with DSP Diva hardware only.

 For Diva 2PRI PCI, Diva 4PRI PCI, Diva 1PRI PCIe HS, Diva 2PRI PCIe HS and Diva 4PRI PCIe HS no
 restrictions apply for this feature and this is possible to access N x 30 DSP resources
 (N - amount of interfaces, 1 - 1PRI, 2 - 2PRI, 4 - 4PRI) in addition to used for E.1/T.1
 DSP resources.

 For Diva PRI Rev.3 PCI and Diva PRI Rev.3 PCIe this is possible to reserve two DSPs for processing
 of E.1/T.1 without media processing features and share remainding DSPs between E.1/T.1 and IP
 for connections with media processing features.
 Using hardware with 30 DSPs and E.1 this is possible to create:
   From:  2 x E.1 without media processing + 28 x E.1 with media processing
   To:   30 x E.1 without media processing + 28 x IP with media processing
 Using hardware with 30 DSPs and T.1 this is possible to create:
   From: 23 x T.1 with media processing    +  7 x IP with media processing
   To:   23 x T.1 without media processing + 28 x IP with media processing

 For Diva BRI-2M Rev.2 PCI, Diva BRI-2M PCIe, Diva 4BRI Rev.2 PCI and for Diva 4BRI PCIe
 this is not possible to reserve DSPs for processing of ISDN connections and to share
 DSPs between ISDN and IP connection. In case DSP resources are assigned to connected
 by IP conference member then appropriate DSP resources receive not available
 for processing of ISDN connections. As result ISDN connections can not be processed.
 To resolve this problem please use Diva configuration to change the configuration
 of Diva board to resourceboardmode. In resourceboard mode ISDN interface is deactivated
 and all available DSP resources (two DSPs for Diva BRI-2M and eight DSPs for Diva 4BRI)
 can be used for connected by IP conference members (two members for Diva BRI-2M and
 eight members for Diva 4BRI).