Problem implementing mixed CSMA and LTE networks

[Fernando Santana]

Hi!

I am a brazilian M.Sc. student and I am doing my research in the evaluation of some reliable transport protocols in LTE networks. We are trying to use the TapBridge with the LTE module and, using the same approach than other researchers, we have mixed CSMA and LTE networks in order to evaluate those scenarios.

We have made several advances... However, there is a problem that we cannot solve... My architecture is depicted below:

LeftHost (10.0.5.1) <=CSMA=> (10.0.5.2) PGW (7.0.0.1) <=PPP=> eNB <=LTE=> (7.0.0.2) UE (10.0.4.1) <=CSMA=> (10.0.4.2) RightHost

The PPP channel is implemented internally by the LTE module (through PointToPointEpcHelper class).

The major problem we have with the implementation is the fact that the packets are traveling from RightHost to LeftHost (e.g., SYN packets are arriving in LeftHost from RightHost), but the response messages are not trespassing the PGW in the opposite direction (from LeftHost to RightHost).

I believe this can be only a routing problem that can be identified by the experts. ;-)

The code we are using is attached to this email, as well as the lxc config files.

I will be very grateful if someone can help me to solve this problem.

Thanks in advance.

--

Fernando Castelo Branco Gonçalves Santana

Mestrando em Ciência da Computação - UFMA

Especialista em Tecnologias em Desenvolvimento para WEB - UFPI

Professor do Ensino Básico, Técnico e Tecnológico - IFPI