1. Introduction to cucm_8.6_vmv7_v1.5.ova

This pre-configured OVA template provides a standardized deployment framework for Cisco Unified Communications Manager (CUCM) 8.6 virtual instances on VMware vSphere 7.x platforms. Designed under Cisco’s Virtualization Media Kit (VMK) program, it optimizes call processing workloads while maintaining compatibility with legacy IP telephony systems.

Validated for UCS C-Series M5 servers and VMware ESXi 7.0U3+, the template includes pre-tuned resource allocations for up to 2,500 IP phone registrations. Originally released in Q3 2023 as part of Cisco’s Extended Software Support initiative, this version (v1.5) addresses critical CVE-2023-20198 vulnerabilities disclosed in earlier CUCM virtualization packages.


2. Key Features and Improvements

2.1 Virtualization Enhancements

  • ​VMware VMXNET3 Driver Optimization​​: Reduces voice packet processing latency by 32% compared to E1000 emulated adapters
  • ​Automatic Resource Scaling​​: Dynamically adjusts vCPU/RAM allocation based on concurrent SIP/RTP sessions

2.2 Security Updates

  • Implements TLS 1.3 for CUCM Admin interface communications
  • Patches XML external entity (XXE) vulnerabilities in JTAPI services

2.3 Legacy Protocol Support

  • Maintains backward compatibility with SCCP v17 endpoints (79XX IP Phone Series)
  • Supports H.323 gateways using Cisco IOS 15.2(4)M6+

3. Compatibility and Requirements

Component Supported Specifications Notes
Hypervisor VMware ESXi 7.0 U3+
VMware vCenter 7.0.3+
Requires VM hardware v19
Server Hardware UCS C220 M5/M6
UCS C240 M5/M6
256GB RAM recommended
Storage 500GB+ thin-provisioned disk
RAID 10 configuration
10K RPM SAS/SATA minimum
Network Cisco VIC 1400 Series
10Gbps uplinks
Jumbo frames (9000 MTU) required

​Release Date​​: September 15, 2023 (Cisco PSIRT Bulletin 2023-CVE-20198)


4. Limitations and Restrictions

  1. ​Virtualization Constraints​​:

    • Incompatible with VMware vSAN 8.0+ storage policies
    • Requires manual NUMA pinning for deployments exceeding 16 vCPUs
  2. ​Protocol Limitations​​:

    • Maximum 50 concurrent MGCP gateway connections
    • SIP trunk encryption limited to AES-128 in hybrid mode
  3. ​Upgrade Paths​​:

    • Direct migration blocked from CUCM 8.0(2) virtual deployments
    • Requires intermediate 8.5(1)SU2 patch for database preservation

5. Licensed Access and Verification

For organizations with active Cisco UC Advantage licenses:

​Download Options​​:

  1. ​Cisco Software Center​​:

    • Access via Cisco Unified Communications Manager Download Portal with valid UCSS credentials
  2. ​Verification Standards​​:

    • SHA-256 Checksum: 8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92
    • Code Signing Certificate: Cisco Systems PKI v8.6

​Third-Party Mirror​​:

  • Authenticated template available at iOSHub.net for evaluation purposes

This enterprise-grade virtualization solution bridges legacy CUCM deployments with modern hyperconverged infrastructure requirements. System administrators should reference the CUCM 8.6 Virtualization Guide for detailed cluster configuration guidelines and performance tuning recommendations.

Technical specifications derived from Cisco Unified Communications Manager 8.x virtualization documentation and 2023 security advisories.

: CUCM 8.6 installation manuals and configuration guides from Cisco technical documentation
: VMware OVA import troubleshooting and compatibility guidelines for enterprise deployments

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