The core function of Riverbed SteelHead appliances is WAN optimization through techniques like data deduplication, compression, and protocol optimization. While QoS (A) can manage congestion and caching (D) can help for static content, the most direct and impactful solution for general application latency over a constrained WAN is to reduce the amount of data sent across it via SteelHead optimization. Increasing bandwidth (C) is costly and does not address the root cause of latency as effectively as optimization.

Layer 2 Bridge Mode places the SteelHead transparently between a router and a switch (or between two switches), operating at the data link layer. It does not participate in routing (no IP on the in-path interfaces), making it invisible to the network’s Layer 3 topology. This satisfies the requirement for no changes to router configs or client gateways. Proxy ARP (B) is an In-Path mode but uses Layer 3. OOP (A) and One-Arm/WCCP (C) require specific routing redirection configurations.

For optimization to be attempted, traffic must first match a rule with an “Optimize” action. If traffic is matching a rule with a “Do Not Optimize” action, or is not matching any rule (and thus using the default pass-through rule), it will not be optimized. While licensing (A) and firewall ports (B) are critical checks, verifying the optimization rule configuration is a more direct and common first step after confirming basic connectivity. Rebooting (D) is a last-resort step, not a standard troubleshooting action.

Transport Flow Optimization (TFO) includes connection management features like idle timeout. If the TFO idle timeout is set lower than the application’s own session timeout, the SteelHead may tear down the optimized connection during user inactivity. The application server, seeing the TCP connection close, may interpret this as a logout, terminating the user’s session. The other features do not directly manage connection longevity in a way that would cause session timeouts.

Virtual In-Path Interfaces (VIPIs) are logical interfaces on the SteelHead used to classify traffic into different service classes. QoS Policies are then applied to these VIPIs to perform traffic shaping, policing, and prioritization (e.g., giving voice traffic a priority queue). This combination allows for effective WAN traffic management directly on the SteelHead appliance.

The Data Store is a fundamental component of Riverbed’s optimization technology. It stores unique chunks of data that have traversed the SteelHead. When the same data chunk needs to be sent again, the SteelHead sends only a reference pointer instead of the actual data. The receiving SteelHead uses its own Data Store to reconstruct the original data. This global deduplication is key to reducing WAN traffic.

The rule list is processed from top to bottom. The correct strategy is to create explicit “Do Not Optimize” rules for non-TCP traffic (like VoIP) and place them above the default rule. The default rule at the bottom should then be set to “Optimize” to catch all remaining TCP traffic. This ensures VoIP passes through, while all other traffic (primarily TCP-based applications) is optimized. Therefore, both statements B and C describe necessary parts of the configuration.

The status “Not Intercepted” specifically means the SteelHead is not actively processing traffic for optimization. This is the operational state when the appliance is in Bypass Mode. Bypass can be triggered manually by an administrator or automatically (via a fail-to-wire card or system fault) to ensure network continuity if the appliance loses power or fails. The other options would result in different statuses, such as “Intercepted” but “Pass-Through” (for C) or “Optimized” but with connection issues (for D).

The software component installed on the endpoint (laptop, tablet, etc.) of a remote or mobile user is the SteelHead Mobile Client (formerly known as the Riverbed Client). This client software intercepts application traffic from the laptop, encrypts it, and sends it over an optimized tunnel to the SteelHead appliance (or SteelHead Mobile Gateway) in the data center, where it is de-duplicated and sent to the final destination.

The core function of Riverbed SteelHead appliances is WAN optimization through techniques like data deduplication, compression, and protocol optimization. While QoS (A) can manage congestion and caching (D) can help for static content, the most direct and impactful solution for general application latency over a constrained WAN is to reduce the amount of data sent across it via SteelHead optimization. Increasing bandwidth (C) is costly and does not address the root cause of latency as effectively as optimization.0