CUCM Video Series

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

TopicsWhat is CUCM Region?Brief introduction to CodecsCommon Codecs G.711, G.729 and iLBCRegion Configuration Steps

CUCM RegionDefines 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.

CodecsThe 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 dont have the same type of codec a Transcoder is required.Traditional Transcoding: G.711 OtherUniversal Transcoding : Other OtherSome codecs are not free to use.Most common codecs for telephony are already available in the Cisco IP Phones.

Common CodecsCodec InformationBandwidth CalculationsCodec & 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 Bytes10 ms4.1160 Bytes20 ms5082.8 Kbps67.6 Kbps87.2 KbpsG.729 (8 Kbps)10 Bytes10 ms3.9220 Bytes20 ms5026.8 Kbps11.6 Kbps31.2 KbpsG.723.1 (6.3 Kbps)24 Bytes30 ms3.924 Bytes30 ms33.318.9 Kbps8.8 Kbps21.9 KbpsG.723.1 (5.3 Kbps)20 Bytes30 ms3.820 Bytes30 ms33.317.9 Kbps7.7 Kbps20.8 KbpsG.726 (32 Kbps)20 Bytes5 ms3.8580 Bytes20 ms5050.8 Kbps35.6 Kbps55.2 KbpsG.726 (24 Kbps)15 Bytes5 ms60 Bytes20 ms5042.8 Kbps27.6 Kbps47.2 KbpsG.728 (16 Kbps)10 Bytes5 ms3.6160 Bytes30 ms33.328.5 Kbps18.4 Kbps31.5 KbpsG722_64k(64 Kbps)80 Bytes10 ms4.13160 Bytes20 ms5082.8 Kbps67.6Kbps87.2 Kbpsilbc_mode_20(15.2Kbps)38 Bytes20 msNA38 Bytes20 ms5034.0Kbps18.8 Kbps38.4Kbpsilbc_mode_30(13.33Kbps)50 Bytes30 msNA50 Bytes30 ms33.325.867 Kbps15.73Kbps28.8 Kbps

G.711ITU-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.729Mostly 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 complexityG.729b, added VAD (Voice Activity Detection).

iLBCInternet 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 ConfigurationSpecify Region Name.Modify Relationship to Other Regions.Set Max Audio Bit RateSet Max Video Call Bit RateSet Link Loss Type

Use System Default will follow the values set in Service Parameter Configuration -> Cisco Call Manager.