If we have mobile network with working 3GDT then a big part of the 3G data traffic goes through the direct tunnel. This is for offloading the SGSN.

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    3gdt               Gi

I was wondering if only the user plane traffic is going through the direct tunnel or a part of the control plane is going through it, too. More specifically I want to know if all the PDP Context activations are counted in the SGSN.

  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer. – Ron Maupin Aug 10 '17 at 3:52

Yes, only user plane traffic (GTP-U) is offloaded directly from RNC to GGSN with 3GDT. Signalling (GTP-C) on Iu-C and Gn-C interfaces is as normal.

  • This is interesting, I didn't know the 3GDT is between the nodeB and the GGSN. I thought in our network it is between the RNC and the GGSN. Are you sure about this – vladiz Jul 8 '15 at 9:39
  • 1
    No, you are right. It is between RNC and GGSN. I am (or was) mostly working with 4G networks so was mostly used to drawing/thinking about those. But the answer still stands - it's only GTP-U that is offloaded! – kll Aug 18 '15 at 18:06

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