a receptacle cage including cage walls forming a cavity, the cage walls including a top wall, a first side wall, and a second side wall, the receptacle cage extending between a front and a rear, the receptacle cage including a channel separator received in the cavity between the first and second side walls, the channel separator including an upper separator wall and a lower separator wall with a separator chamber between the upper and lower separator walls, the channel separator separating the cavity into an upper module channel configured to receive an upper pluggable module and a lower module channel configured to receive a lower pluggable module, the top wall including a top opening providing access to the upper module channel, the lower separator wall including a lower opening providing access to the lower module channel, the first side wall including a side opening aligned with the separator chamber; and

a thermal transport assembly coupled to the receptacle cage, the thermal transport assembly including an upper cooling module, a lower cooling module and a cold plate at the rear of the receptacle cage, the upper cooling module being located in the top opening, the upper cooling module thermally coupled to the cold plate and configured to be thermally coupled to the upper pluggable module plugged into the upper module chamber, the lower cooling module being located in the separator chamber, the lower cooling module being loaded into the separator chamber, the lower cooling module thermally coupled to the cold plate and configured to be thermally coupled to the lower pluggable module plugged into the lower module chamber.