TonB protein found in E.coli interacts with receptor proteins located on the outer membrane in a coupled form so as to carry out high-affinity binding and ATP-dependent uptake of substrates into the periplasmic space; this is however substrate specific, and highly specialised. So, it can thus be said that they indirectly act as porins, albeit in a coupled form with receptor proteins present
TonB protein interacts with outer membrane receptor proteins that carry out high-affinity binding and energy-dependent uptake of specific substrates into the periplasmic space.(Koebnik R (2005). "TonB-dependent trans-envelope signalling: the exception or the rule?". Trends Microbiol. 13 (8): 343–347)
Porins are beta barrel proteins that cross a cellular membrane and act as a pore through which molecules can diffuse. Unlike other membrane transport proteins, porins are large enough to allow passive diffusion. https://www.nlm.nih.gov/cgi/mesh/2011/MB_cgi?mode=&term=Porins