Core Issue
To reduce delay for voice packets and improve voice quality, reduce serialization delay by segmenting large data packets.
Resolution
Frame Relay Fragmentation (FRF.12) is useful in reducing serialization delay where Permanent Virtual Circuits (PVCs) to remote sites are less than 768 Mbps.
Before configuring this feature, note that most connections of this type have some form of Frame Relay Traffic Shaping (FRTS). For more information, refer to the FRTS for Voice section of VoIP over Frame Relay with QoS (Fragmentation, Traffic Shaping, Low Latency Queueing [LLQ] and IP Real-Time Protocol [RTP] Priority).
For more information about fragmentation, refer to the Fragmentation (FRF.12) section of VoIP over Frame Relay with QoS (Fragmentation, Traffic Shaping, LLQ and IP RTP Priority).
FRF.12 was first introduced in Cisco IOS Software version 12.0(4)T and is available in plus feature sets thereafter. For supported releases across platforms and FRF.12 supported releases, refer to the Software Advisor.
Voice Quality
Choppy voice (Listen to short or long choppy voice samples.)
Synthetic voice (Listen to short or long synthetic voice samples.)