# Digital text can be blocked · Worked example

- One sentence for blank text and one for a dropped call.
- Name the suspect for each
- Name the retest
- The sentences do not share a fix.

## Sources and go deeper

- [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.
- [ITU-T E.164, international public telecommunication numbering](https://www.itu.int/rec/T-REC-E.164). standard. last checked 2026-10.