I do not know about Comcast , but this modem work well with Charter . I check Charter 's instruction for install a new modem and they basically say the opposite of what happen -lrb- need to update they site -rrb- , but I hook it up and all I have to do be follow the screen prompt . just one little problem that be resolve by call Charter : if there be a router install , do this and avoid the call : shut down computer , router , old modem . install new modem and start up everything in the order of new modem , router , computer . follow the screen prompt . now what happen be , it do not seem to finish the connection , so do this : shut down computer and router . -lrb- do not shut down the new modem -rrb- Start router , then computer , and it will complete the install . I have have no problem with this modem and can easily stream to the tv through it and the older Cisco wireless router install .