There are 2 types of security in Service Broker: dialog and transport. Dialog security establishes a secure, authenticated connection between Service Broker Services or dialog endpoints. Transport security establishes an authenticated network connection between SQL Server instances or Service Broker endpoints. Clear as mud, right? Don’t worry, these are easily mixed up by both novice and experienced Service Broker admins. To illustrate, let’s go back to our taxes scenario. You’ve completed your forms, stamped your envelope and you’re ready to mail it in. You drop it in your nearest mailbox and what happens next? A postal worker will pick it up, it gets loaded into a truck and shipped between various sorting facilities (as you might have noticed I have no clue how the USPS works) until it is finally delivered to the IRS via yet another postal worker. Now, those postal workers all have the authority to transport your tax return from point to point. However, they do not have the authority to open up and read your return. That’s what transport security is. The IRS agent on the other end, though, he does have the authority to read your return. That’s dialog security.
It’s also worth noting that transport security is only needed in a distributed environment. Just like if the IRS agent lived with you, you wouldn’t need to go through the USPS. But that’s just weird.
This wraps up Colleen’s Service Broker series. If you do find yourself interested in Service Broker, this is a great way to get your feet wet.