Your service provider should not need to access your facility unless there's a hardware failure. To save time and money, service providers will normally fix the hardware using out-of-band connections such as modems, or will ask to walk you through the steps of fixing the hardware, before they send engineers to your site to fix or swap the hardware.

When the hardware is installed on your site, it's critical that the service provider has some type of out-of-band management to the hardware, e.g., a modem connection to the console port. Without that, it's likely that you will need staff on hand at all times to help support the service provider.

In most cases, when the hardware is installed on the customer's premises, service providers cannot provide spare parts to that site. When the hardware fails, the service provider needs to ship the replacement and install it when it gets there. Ensure that the SLA clearly states the amount of time it takes to ship and install the hardware. Do not accept anything slower than next-day shipping; anything longer will leave your network at risk.

If uptime is critical (and who can afford downtime?) for the location, take the high-availability options for the hardware or look for a service provider that can offer on-site visits in two to four hours. However, keep in mind that these services will usually have a fairly high premium.

Given uptime or service availability is the most critical factor for service measurement, most service providers offer high-availability (HA) options for your service. Most often you will see active-standby configurations. Some service providers offer clustered offerings in active-active configuration. The clustered application is usually more expensive, and overall HA offerings should be less expensive than contracting for two hardware installations together. For services that include hardware installed on the customer's site, HA configuration is highly recommended, as you don't want your network to be without protection when the hardware fails.