The Columbia Encyclopedia, Sixth Edition. 2001-05.

Sarmatia


(särm´sh) (KEY) , ancient district between the Vistula River and the Caspian Sea, occupied by the Sarmatians [Lat. Sarmatae] from the 3d cent. B.C. through the 2d cent. A.D. The term is vague and is also used to refer to the territory along the Danube and across the Carpathians where the Sarmatians were later driven by the Huns. The Sarmatians, who until c.200 B.C. lived E of the Don River, spoke an Indo-Iranian language and were a nomadic pastoral people related to the Scythians (see Scythia), whom they displaced in the Don region. The main divisions were the Rhoxolani, the Iazyges, and the Alans or Alani. They came into conflict with the Romans but later allied themselves with Rome, acting as buffers against the Germans. They were scattered or assimilated with the Germans by the 3d cent. A.D.
See study by T. Sulimirski (1970).


The Columbia Encyclopedia, Sixth Edition. Copyright © 2001-05 Columbia University Press.
This would lead me to assume that they were chumming around with the Sauromatae. Most likely a subjugated tribe. But I am no expert.