In Cisco IOS gateways, DSP is required when?

• A. When hardware-based media services are needed.
• B. When software-based voice processing is sufficient.
• C. Only for video endpoints.
• D. When SIP trunking is not available.

Answer: (A)

DSPs in Cisco IOS gateways provide hardware-based media processing, handling real-time tasks such as transcoding between codecs, conferencing, and advanced audio features like echo cancellation. They’re required whenever you need hardware-accelerated media services because relying on the main CPU for these tasks can become a throughput or latency bottleneck. If the system can meet quality and performance requirements with software-based voice processing on the CPU, DSPs aren’t strictly required. This isn’t determined by SIP trunking availability, and while some video scenarios can benefit from DSP processing, the deciding factor is whether you need hardware-assisted media handling rather than the type of endpoint.