Fragmented UDP SIP packets causing “dead air”

This is the first in a series of (long overdue) posts related to odd bugs and behavior experienced in the Cisco Unified Border Element (CUBE) which is built into Cisco IOS. I will spare you all the details, but high level our environment looks like this:

  • Cisco Unified Communications Manager (CUCM) – multisite deployment with centralized call processing with geographical diversity
  • Contact Center – Cisco CVP including Call StudioUCCE, Nuance ASR/TTS, Cisco Unified Presence Server (SIP Proxy)
  • SIP Trunks with CUBE for Local/Long-Distance and Inbound Toll-Free

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