Monitoring the amount of transmitted/received data

[mohamedtaha84]

I have TP-Link Router at home.
I'm using cacti installed on RaspberryPi to graph the SNMP counters on the router interfaces.
Everything is working fine when it comes to monitor the traffic bitrates (bits/sec).

I want to monitor the amount of transmitted/received bytes through the interfaces, using the SNMP counters ifInOctets and ifOutOctets over time.
Think about it like a buildup graph like the "data usage" graph in andriod to monitor the sent/received data.

The problem that the snmp counters are 32 bits, which will "wrap up" after about 4 GB, while I'm using the interfaces for much higher data transfers (I have a NAS solution inside my home network).

I'm using 30 seconds step for the poller and data source to avoid the mis-interpretation of the 32 bit counters (avoid counter wrap ups during the sampling period), the router have 1Gbps interfaces, which can cause counter wrap ups in about 34 seconds.

So I need to a way to implement such a graph.

Thanks in advance.