Few resources RIPv2 daemon

I want a RIPv2 daemon that uses few resources, only for my ISP's VoIP.

I only found packages for bird and frr which of the two would you recommend. It looks like they both include several routing protocols, is there any other daemon I haven't seen?

I would have suggested zebra but it looks like that's encapsulated in frr.

I have to ask though: why do you need a routing protocol to do VoIP?

It is the VoIP service offered by my ISP for landlines. On the ISP's official router they configure the VLAN for VoIP via DHCP and create a RIPv2 session so I am copying the configuration.