The repair-time guarantee (GTR in France, tied to MTTR) is the contractual commitment to fix a failed link within a maximum delay. Three levels exist:
- 4 business hours, often sold as a “4h pro” SLA: restored within 4 hours during business hours (working days, office window). The standard for business access (FTTO/FTTE).
- 4h 24/7: the same 4 hours, but including nights, weekends and holidays — for a site that runs around the clock.
- 2h: reserved for critical access, and the most expensive.
If exceeded, penalties apply, but they are capped: read the cap before relying on it — it rarely covers the real cost of an outage.
The guarantee is THE difference between dedicated business fiber (FTTO/FTTE) and shared consumer fiber (FTTH): FTTH costs 5 to 10 times less, but without one an outage can last days. Best practice is not necessarily paying for guarantees everywhere: on a secondary site, FTTH doubled with 4G/5G backup often delivers better real availability than a single guaranteed link, for less money. Reserve short repair guarantees for sites where every hour of downtime costs. For what a contractual commitment is really worth, see our GTR, SLA and MTTR guide.