# The desktop review

- A desktop review is short: one screen, WSS through the proxy, TLS 1.2, the schedule visible, text not blocked, USB headset, supported path, Efficiency Mode off, and the bandwidth rows added up. Each line is from the product page or the PDF.
- If those pass and audio is still one-way, you are in NAT and firewall territory, which is the SIP track. The desktop is no longer the prime suspect.
- Run the desktop review
- Escalate one-way audio to the network track

## Sources and go deeper

- [Agent Desktop](https://www.five9.com/products/capabilities/agent-desktop). vendor. last checked 2026-10.
- [Technical requirements PDF](https://documentation-be.five9.com/bundle/five9-technical-requirements/raw/resource/enus/five9-technical-requirements.pdf). vendor. last checked 2026-10. Fetched for this lab in October 2026. Re-read before you buy hardware or open a firewall.
- [IANA service names and port numbers](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml). ports. last checked 2026-10.
- [RFC 3261, SIP: Session Initiation Protocol](https://www.rfc-editor.org/rfc/rfc3261). rfc. last checked 2026-10.
- [RFC 8446, TLS 1.3](https://www.rfc-editor.org/rfc/rfc8446). rfc. last checked 2026-10.
- [RFC 6455, The WebSocket Protocol](https://www.rfc-editor.org/rfc/rfc6455). rfc. last checked 2026-10.
- [RFC 1918, private internet addresses](https://www.rfc-editor.org/rfc/rfc1918). rfc. last checked 2026-10.
- [RFC 4787, NAT behavior for UDP](https://www.rfc-editor.org/rfc/rfc4787). rfc. last checked 2026-10.