ADSL upgrade

[Agro_EF]

Hi all i need to know one simple thing and i hope the techs in AFF are easyer and can talk english unlike our most un fav telstra personal ( well thats enougth of a whinge of them) i have a speedstream modem and i brought a billion BIPAC 5102 , 4 port modem and telstra says it wont work with bigpond is this true , as if this false well can someone explain how to do it, as telstra says to buy a 510 are they pulling my chain as in saying but there gear or am i wrong about telstra