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

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

3. 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.

4. 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.

5. Common Codecs Codec Information Bandwidth Calculations
Codec & Bit Rate (Kbps)
Codec Sample Size (Bytes)
Codec Sample Interval (ms)
Mean Opinion Score (MOS)
Voice Payload Size (Bytes)
Voice Payload Size (ms)
Packets Per Second (PPS)
Bandwidth MP or FRF.12 (Kbps)
Bandwidth w/cRTP MP or FRF.12 (Kbps)
Bandwidth Ethernet (Kbps)
G.711 (64 Kbps)
80 Bytes
10 ms
4.1
160 Bytes
20 ms 50
82.8 Kbps
67.6 Kbps
87.2 Kbps
G.729 (8 Kbps)
10 Bytes
3.92
20 Bytes
26.8 Kbps
11.6 Kbps
31.2 Kbps
G (6.3 Kbps)
24 Bytes
30 ms
3.9
33.3
18.9 Kbps
8.8 Kbps
21.9 Kbps
G (5.3 Kbps)
3.8
17.9 Kbps
7.7 Kbps
20.8 Kbps
G.726 (32 Kbps)
5 ms
3.85
50.8 Kbps
35.6 Kbps
55.2 Kbps
G.726 (24 Kbps)
15 Bytes
60 Bytes
42.8 Kbps
27.6 Kbps
47.2 Kbps
G.728 (16 Kbps)
3.61
28.5 Kbps
18.4 Kbps
31.5 Kbps
G722_64k(64 Kbps)
4.13
67.6Kbps
ilbc_mode_20(15.2Kbps)
38 Bytes NA
34.0Kbps
18.8 Kbps
38.4Kbps
ilbc_mode_30(13.33Kbps)
50 Bytes
Kbps
15.73Kbps
28.8 Kbps

6. 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.

7. 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.729a and G.729b.
G.729a, medium complexity
G.729b, added VAD (Voice Activity Detection).

8. iLBC 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.

9. 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.