Create a common VLAN in two 3448P

Um, yeah, create the vlan on both switchs and make the two ports a member of that vlan.  Are the two ports the ports that the switches are connecting to each other with.  If not, then you need to also add those ports to the mix.  If they are, then that makes no sense as to why you are doing that.  I hope its not the latter.  Also, if you already have a connection between the two switches, you will need to make those ports that connect the two switches trunk ports so they can pass multiple vlans.