Some ideas:

• Reduce precision or the amount of detail you show in the business context. Show abstractions, aggregate neighbors or even interfaces.
• Show categories (or clusters) of neighbors, not every single neighbor system.
• Use UML port symbols on a component diagram to avoid drawing too many boxes and lines
• Combine multiple types of users or user-roles into appropriate abstractions or more generic roles (e.g. combine private and corporate users simply into “users”).