We have 3 application specific agile teams underneath one large product. There exists a need for cross team communication, that is where the Scrum of Scrums comes in.
What is the Scrum of Scrums?
Scrum of Scrums (SOS) is a daily standup comprised of the Scrum Master from each team in order to facilitate cross team communication.
SOS occurs after all agile teams have completed theirs. We ask the same questions as in an agile team stand up but on a team level instead of an individual level:
1. What did you do yesterday?
2. What are you doing today?
3. What, if any, roadblocks exist?
4. One additional question: team ideas or gauges of teams feedback.
At the end of the iteration, we have our morning Iteration Retrospective and Planning Meeting <LINK>. That afternoon, the SOS will meet to compose an e-mail with each team's action items. One Scrum Master will e-mail everyone (all teams) with all action items, if a team member has questions, they will be encouraged to speak with their Scrum Master. This serves as one point of contact and also documentation of the action items.
For us, this has been a good form of cross team communication and has also spurred conversation/ideas that would effect all teams such as changing Source Control Versioning System or blocks of code that would effect an underlying architecture.
Jerrel Blankenship Blog