What feature is used to bypass SGSN on data path?

Question

Options

• Amobile Internet fast path
• Bdirect tunnel
• CGTP-U tunnel
• Dtwo tunnel

• A
  9% (5)
• B
  86% (50)
• C
  3% (2)
• D
  2% (1)

Explanation

Direct Tunnel (B) is the 3GPP feature that removes the SGSN from the user plane data path by establishing a GTP-U tunnel directly between the RNC (Radio Network Controller) and the GGSN, while the SGSN still handles control plane signaling. This reduces latency and offloads data processing from the SGSN.

Why the others are wrong:

• A (mobile Internet fast path) - Not a standard 3GPP term; a distractor with no specific technical definition in this context.
• C (GTP-U tunnel) - GTP-U is the protocol used to carry user-plane data in GPRS/UMTS networks generally, including in direct tunnel - it's a component, not the feature that bypasses the SGSN.
• D (two tunnel) - This actually describes the normal (non-optimized) architecture, where two GTP-U tunnels exist: RNC→SGSN and SGSN→GGSN. Direct tunnel collapses this into one.

Memory tip: Think of it literally - "direct tunnel" means going directly to the GGSN, cutting out the SGSN middleman on the data path. If you remember that normal traffic takes two hops (two tunnels), then the optimization that removes a hop must be the direct (one-hop) tunnel.

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