If your business runs on Cisco voice infrastructure, you’ll want to pay attention to this.
Cisco has announced the end-of-life for its Unified SIP Proxy (CUSP), the signaling platform that’s quietly been routing, securing, and managing SIP traffic in the background of many enterprise voice environments.
CUSP’s retirement is a signal from Cisco that their roadmap is evolving. And if you rely on CUSP today, it’s time to start thinking about what comes next.
What is Cisco CUSP?
Cisco Unified SIP Proxy (CUSP) is a Session Initiation Protocol (SIP) proxy that helps manage SIP call signaling between different devices and systems like your Session Border Controllers (SBCs), IP PBXs, and PSTN gateways. It’s used to:
- Route SIP traffic intelligently
- Maintain call control and failover
- Provide protocol normalization
- Secure VoIP traffic
In short, CUSP has been a critical component for organizations with complex, distributed voice deployments.
Why Is Cisco Retiring CUSP?
Cisco is consolidating its voice and collaboration tools and moving toward more cloud-centric, software-defined architectures. CUSP hasn’t received major updates in years, and with rising adoption of Webex Calling, CUCM upgrades, and third-party SBCs, Cisco sees less need to maintain a standalone SIP proxy.
The official end-of-support date for CUSP is January 2025, and new feature development has already ceased.
What Does This Mean for You?
If you’re currently using CUSP, there are a few key implications:
- No new features or bug fixes
Security patches will be limited, and over time, compatibility issues may arise with other platforms. - Increased operational risk
As CUSP ages, your environment becomes more brittle and harder to support, especially if your SIP topology depends on it. - Time to plan a migration
Whether you’re staying on-prem or moving toward the cloud, you’ll need a strategy for rerouting SIP traffic and maintaining resiliency.
What Are the Alternatives?
Replacing CUSP isn’t necessarily a one-to-one swap. This is a chance to rethink how your SIP traffic is managed. Common options include:
- Third-party Session Border Controllers (SBCs)
Vendors like Ribbon, AudioCodes, and Oracle offer robust SIP routing and security features. - Cloud voice platforms with built-in SIP handling
Webex Calling, Microsoft Teams, Zoom Phone, and others manage SIP infrastructure for you, reducing complexity. - Managed SIP services
Some organizations offload SIP routing entirely to a carrier or managed service provider.
What Should You Do Next?
- Take inventory
Identify where and how CUSP is used in your network. - Evaluate your SIP architecture
Consider whether you want to replicate what CUSP did or redesign your voice routing model for the future. - Talk to a tech advisor
A partner that understands both legacy Cisco and modern voice solutions can help chart a practical, cost-effective path forward.
Final Thoughts
Cisco’s move to retire CUSP is a nudge to modernize. Whether that means leaning into cloud calling or simplifying on-prem SIP routing, now’s the time to take action.
Need help navigating the transition? We work with top SIP, SBC, and cloud voice providers to help businesses future-proof their communications stack.
