The Gateway Servers roles, yes there are more than one role that it plays which are not for the most part vital to achieve out of domain connectivity. But any of us deploying cert’s realise this is the best solution for more than 10 clients outside of your domain.

So what is the Gateway server? Well it is a cut down version of a management servers, one of the features removed is the lack of a console. Much like a proxy in nature but named correctly because it creates a Gateway into the Operations Manager System.

For your info the Gateway server is also licensed the same as Management Server or RMS, value for money, oh yes. Operations Manager out of the domain or Kerberos requires PKI on each client unless you have a Gateway Server. Then you only need one as each client will connect to the Gateway Server, same as client connecting to a MS where it in turn passes the info onto the MS with benefits like tighter Firewall security, less band width and loads of reduced admin. In fact it is possible to deploy into another domain with a Gateway Server even discover.

We can add multiple Gateway servers if needed for fault tolerance etc so clearly a major part of the Ops Mgr system.

When implementing multiple Gateway servers, it is important to keep in mind that each Gateway server is afforded the same amount of processing time as a standard agent. This can be a significant issue when a Gateway Server, which has (for example) 20 agents assigned to it, is reporting to a Management Server that also has (for example) 149 Agents assigned to it. Effectively, the Gateway server will have 1/150th share of processing time which can cause a significant bottleneck. Based on this, Microsoft recommend having a dedictaed Management Server solely responsible for Gateway assignment.