Riverbed Cloud Services : System limitations and dependencies : Limitations on AWS
  
Limitations on AWS
This section describes the deployment and feature options that the SteelHead-c for AWS does not support.
Deployment limitations
Automatic peering - The SteelHead-c does not use automatic peering. When you run a server in the cloud, you deploy the SteelHead-c to be the furthest SteelHead in the network, because
the Discovery Agent on the server is configured to use the SteelHead-c automatically. When you run a client in the cloud, and there are multiple SteelHeads in the path to the server, the SteelHead-c is selected for optimization first. You can enable automatic peering on the remote SteelHeads to make
the SteelHead-c peer with the furthest SteelHead in the network.
Simplified routing - The SteelHead-c for AWS is not deployed in-path, but rather in its unique
out-of-path method using one interface. Simplified routing does not apply.
WCCP/PBR/L4 - The SteelHead-c for AWS uses a unique redirection mechanism that enables deployments in any cloud environment. The SteelHead-c also supports WCCP/PBR/L4 redirection when made available by the cloud provider. Amazon EC2 does not support these traditional redirection mechanisms.
Connection forwarding - The SteelHead-c uses a unique out-of-path method; connection forwarding does not apply.
Feature limitations
RSP - The SteelHead-c for AWS is a virtual SteelHead deployed into the AWS virtualization environment. You need not run virtualization on top of virtualized software.
PFS - It is easier and simpler for you to run a separate file server instance in the cloud and not use the SteelHead for Proxy File Service (PFS).
WAN visibility mode - The SteelHead-c currently supports only correct addressing. It does not support full transparency and port transparency.
CIFS prepopulation - CIFS prepopulation is not supported on the SteelHead-c for AWS because it requires the Riverbed Copy Utility (RCU) to run on a different interface. Prepopulation also requires a switch to make the traffic loop back through the SteelHead, which is not possible in the cloud. If you want prepopulation, you can install the RCU or a similar tool on a machine in the cloud. You would most likely configure prepopulation on the remote SteelHead instead of the SteelHead-c.