Cisco Unified Communications Manager CUCM Video 2 Region

Cisco Unified Communications Manager (CUCM) Video #2: Region

Topics • What is CUCM Region? • Brief introduction to Codecs • Common Codecs – G. 711, G. 729 and i. LBC • Region Configuration Steps

CUCM Region • Defines the maximum bit rate between group of IP Phones. • Codecs that have higher bit rate than the value set in Region will not be used between IP Phones. • Region is used to for bandwidth sizing. • Codecs will determine how many calls are possible for a given bandwidth.

Codecs • The word CODEC is taken from the words COder and DECoder. • Codecs are used for compression and decompression of audio signals. • Not all audio codecs can be used for telephony. • IP Phones need to have the same Codec to play the audio stream both ways. If IP Phones don’t have the same type of codec a Transcoder is required. – Traditional Transcoding: G. 711 <-> Other – Universal Transcoding : Other <-> Other • Some codecs are not free to use. • Most common codecs for telephony are already available in the Cisco IP Phones.

Common Codecs Codec Information Codec & Bit Sample Rate (Kbps) Size Interval (Bytes) (ms) G. 711 (64 80 Bytes 10 ms Kbps) G. 729 (8 10 Bytes 10 ms Kbps) G. 723. 1 (6. 3 24 Bytes 30 ms Kbps) G. 723. 1 (5. 3 20 Bytes 30 ms Kbps) G. 726 (32 20 Bytes 5 ms Kbps) G. 726 (24 15 Bytes 5 ms Kbps) G. 728 (16 10 Bytes 5 ms Kbps) G 722_64 k(64 80 Bytes 10 ms Kbps) Bandwidth Calculations Mean Opinion Score (MOS) Voice Packets Per Bandwidth MP Bandwidth Payload Size Second or FRF. 12 w/c. RTP MP or (Bytes) (ms) (PPS) (Kbps) FRF. 12 (Kbps) Bandwidth Ethernet (Kbps) 4. 1 160 Bytes 20 ms 50 82. 8 Kbps 67. 6 Kbps 87. 2 Kbps 3. 92 20 Bytes 20 ms 50 26. 8 Kbps 11. 6 Kbps 31. 2 Kbps 3. 9 24 Bytes 30 ms 33. 3 18. 9 Kbps 8. 8 Kbps 21. 9 Kbps 3. 8 20 Bytes 30 ms 33. 3 17. 9 Kbps 7. 7 Kbps 20. 8 Kbps 3. 85 80 Bytes 20 ms 50 50. 8 Kbps 35. 6 Kbps 55. 2 Kbps 60 Bytes 20 ms 50 42. 8 Kbps 27. 6 Kbps 47. 2 Kbps 3. 61 60 Bytes 30 ms 33. 3 28. 5 Kbps 18. 4 Kbps 31. 5 Kbps 4. 13 160 Bytes 20 ms 50 82. 8 Kbps 67. 6 Kbps 87. 2 Kbps ilbc_mode_20 38 Bytes 20 ms (15. 2 Kbps) NA 38 Bytes 20 ms 50 34. 0 Kbps 18. 8 Kbps 38. 4 Kbps ilbc_mode_30 50 Bytes 30 ms (13. 33 Kbps) NA 50 Bytes 30 ms 33. 3 25. 867 Kbps 15. 73 Kbps 28. 8 Kbps

G. 711 • ITU-T standard. Used in the PSTN (Public Switched Telephony Network and most IP PBX implementations. • Comes in two variants – u-law and a-law. • U-law is commonly used in the United States, North America and Japan. A-law is used anywhere else. • Medium complexity codec – uses less computational resources.

G. 729 • Mostly used in VOIP applications due to low bandwidth requirements. • Commonly used for calls outside the IP LAN environment. • Good for Latin Based language but not fit for music on hold. • Has several two main variants of the original – G. 729 a and G. 729 b. – G. 729 a, medium complexity – G. 729 b, added VAD (Voice Activity Detection).

i. LBC • Internet Low Bitrate Codec – released in 2004. • Was used in Yahoo Messenger, Gtalk and older versions of Skype. • Royalty free – no need to pay to use.

Region Configuration • Specify Region Name. • Modify Relationship to Other Regions. – Set Max Audio Bit Rate – Set Max Video Call Bit Rate – Set Link Loss Type • “Use System Default” will follow the values set in Service Parameter Configuration -> Cisco Call Manager.