A Little Wiki History on Selsius Systems
Selsius Systems, Inc. was organized in July, 1997 as a wholly owned subsidiary of Intecom, a Dallas based Private Branch Exchange or PBX manufacturer, with David C. Tucker as CEO, Richard B. Platt as VP of Engineering and Kevin Brown as VP of Sales and Marketing, as well as numerous other important positions held by the employees of Selsius Systems including John Alexander, Paul Hahn, Dave Corley, Jeff Sanders, and Scott Veibell. Cisco acquired SCCP technology when it acquired Selsius Corporation in 1998. This was the beginning of skinny or SCCP.If you have ever wondered where the SEP on the description of a Cisco Phone comes from or what it means now you know. It stands for Selsius Ethernet Phone.
SCCP or Skinny Call Control Protocol
The Skinny Client Control Protocol or SCCP is the Cisco standard for real-time calls and conferencing over Internet Protocol (IP). With SCCP a Cisco IP Phone can co-exist in an H.323 environment. When Cisco CallManager is coupled with an H.323 Gatekeeper or an MGCP Call Agent, a Cisco ATA or DSP Farm running SCCP interoperates with H.323 terminals on the far end to establish, control and clear audio calls.
Building A SCCP DSP Farm
R1#config t R1(config)#voice-card 0 R1(config-voicecard)#dspfarm R1(config-voicecard)#dsp services dspfarm R1(config-voicecard)#exit R1(config)#exit R1#
Watch your identifier and priority. This should coincide with your Call Manager Group in the Device Pool configuration. In other words the Device Pool assigned to the Phones should coincide with either the Publisher or the Subscriber.
R1#config t R1(config)#sccp local GigabitEthernet0/0.2 R1(config)#sccp ccm 192.168.1.20 identifier 1 priority 1 version 7.0 R1(config)#sccp ccm 192.168.2.20 identifier 2 priority 2 version 7.0 R1(config)#sccp R1(config)#exit R1#
The following profile names must be built out in Call Manager underneath the Media Resources. You can use any name that makes sense to you but they need to match. This also makes future administrations much easier. You can also define your codec complexity and needs depending on the DSP resources you have available. Depending on your Gateway the DSP resources required may vary greatly. For example a PRI ISDN / PSTN Gateway is going to require a lot more DSP resources then a standard POTS Gateway. It’s almost a 1 to 1 DSP resources for every channel of ISDN PRI.
The names you choose to use are of course up to you, but they need to match the configuration within Call Manager.
R1#config t R1(config)#sccp ccm group 3 R1(config-sccp-ccm)#associate ccm 1 priority 1 R1(config-sccp-ccm)#associate ccm 2 priority 2 R1(config-sccp-ccm)#associate profile 3 register R1-MTP R1(config-sccp-ccm)#exit R1(config)#
R1(config)#sccp ccm group 2 R1(config-sccp-ccm)#associate ccm 1 priority 1 R1(config-sccp-ccm)#associate ccm 2 priority 2 R1(config-sccp-ccm)#associate profile 2 register R1-CFB R1(config-sccp-ccm)#exit R1(config)#
R1(config)#sccp ccm group 1 R1(config-sccp-ccm)#associate ccm 1 priority 1 R1(config-sccp-ccm)#associate ccm 2 priority 2 R1(config-sccp-ccm)#associate profile 1 register R1-TRANS R1(config-sccp-ccm)#exit R1(config)#
R1(config)#dspfarm profile 1 transcode R1(config-dspfarm-profile)#codec g711ulaw R1(config-dspfarm-profile)#codec g711alaw R1(config-dspfarm-profile)#codec g729ar8 R1(config-dspfarm-profile)#codec g729abr8 R1(config-dspfarm-profile)#codec g729r8 R1(config-dspfarm-profile)#maximum sessions 2 R1(config-dspfarm-profile)#associate application SCCP R1(config-dspfarm-profile)#exit R1(config)#
R1(config)#dspfarm profile 2 conference R1(config-dspfarm-profile)#codec g711ulaw R1(config-dspfarm-profile)#codec g711alaw R1(config-dspfarm-profile)#codec g729ar8 R1(config-dspfarm-profile)#codec g729abr8 R1(config-dspfarm-profile)#codec g729r8 R1(config-dspfarm-profile)#codec g729br8 R1(config-dspfarm-profile)#maximum sessions 2 R1(config-dspfarm-profile)#associate application SCCP R1(config-dspfarm-profile)#exit R1(config)#
R1(config)#dspfarm profile 3 mtp R1(config-dspfarm-profile)#codec g711ulaw R1(config-dspfarm-profile)#maximum sessions software 250 R1(config-dspfarm-profile)#associate application SCCP R1(config-dspfarm-profile)#exit R1(config)#exit R1#
