Task status tab of the agent shows a distant site server and the agent should be registered to a closer one.
Package delivery takes longer than expected or not at all.
Understanding site services
Connection to a task server is over the 'tickle' port, 50124. This is used for quick delivery tasks such as run script or power control.
If your machines are not manually assigned a task server then 'task agent settings' govern which task server an agent will connect to.
Task agent settings give three options. Either choose a task server based on remaining capacity, fastest connection speed, or fewest computers connected.
Typically it's recommended to use the fastest connection speed to keep your agents registered to geographically nearby task servers.
An agent pulls down client policy XML from the NS on a regular schedule determined by targeted agent settings. The agent then requests codebase from the NS for any packages associated with those policies that are in the client policy. The NS decides which site server(s) codebase information to distribute based on the subnet of the agent performing the request. If a machine's subnet is not associated to a site and subsequently a site server running package service then the machine cannot download from the intended site server. Make sure that your machine's subnet is listed in a site and that site is associated with a package server. Or manually assign the machine to the site server.
Network Boot Service:
Pulling down an image is very similar to pulling down a software package. The DS agent does a GetNearestPackageServerInfo request to determine which package server to pull the image from.
Understanding functional differences between Task Server registration and Package Server assignment:
The task server an agent is registered to does not dictate where its packages or DS images come from. Only the subnet to site and site to Site Server association determines Package Server assignment.