Many ASPs, including some that offer multiple hosting centers, do not support replication. ASPs also cite synchronization difficulties and the scarcity of technical talent required for supporting mirrored sites. ASPs also differ in hardware and systems software. Before choosing an ASP, you need to consider what impact the ASP's limitations on back-end runtime architectures might have on performance, ongoing support, and overall costs. This is obviously a key consideration.
ASPs offer a variety of network options for accessing the hosted applications.
Internet-based access is particularly sticky. Public peering points are subject to high volumes of traffic that can severely reduce access times. To optimize performance, ASPs should provide diverse and redundant connections that avoid public NAPs. ISPs that offer application-hosting services often employ their own backbone to provide a direct pathway to global Internet destinations. Other ASPs avoid congested NAPs by forming private peering points with other carriers.