LTE UDP packet to a UE using a relay node (Wifi AP).

[Farooque Hassan]

Hello All,

         The scenario I designed is a combination of THIRD.cc and LTE-SIMPLE-EPC.cc files. Wifi devices are connected to an AP and AP is attached to eNodeB. A UDP packet from remote server is destined to UE 1. The packet reaches to wifi AP, but it does not sends it the UE. The packet transfer from wifi AP are only beacons, ACK signals.

The flow monitor shows that uplink from UE to remote server has 100% packet loss. However, downlink from remoter server to UE has 0% packet loss. I think there is something missing in Wifi AP, so that it can work as a relay to and from UE. Any suggestion are welcome. 

Thank You.

[Tommaso Pecorella]

Hi,

are you sure that packets are forwarded ? In other terms, did you set the routing in the right way ?

The second point is: EPC does "know" that the UE is a router ? Usually the EPC assigns only one IP number to the UE (in IPv4 case) and forwards only that one.

T.

[Farooque Hassan]

Thanks Tommaso Pacorella,

              I rechecked my Code. For Routing in AP (Wifi), I had to add an static route using correct network address and Iface value. Luckily, I came across to routing table (From dynamic-global-routing.cc) and checked Iface value for LTE network in AP's routing table. After adding a static route for remote server in AP, the AP is able to identify its path.

Thank You For Prompt Response. I did it for only Uplink. I will check for Downlink Now.. :) 

[Konstantinos]

Hi Farooque,

The downlink will not work with simply creating static routes.

The issue has been discussed previously in the list and it is due to the lack of NAT implementation. (https://groups.google.com/d/msg/ns-3-users/Z7Jbw0fFujQ/eSMZbdyITggJ)

The EPC is able to route only towards the UE and is unaware of any other routes that the UE may have.

K.

[Farooque Hassan]

Hello Konstantinos,

               Thank You for the heads up. This will definitely save time for me. Thank You...