You either need to set your router to turn on uPnP or go in and open up all the Xbox ports manually.
Application Protocol/port Direction Network
svchost.exe UDP 1900 Outbound, Inbound Local Subnet
svchost.exe TCP 3390 Inbound Local Subnet
svchost.exe TCP 2177 Outbound, Inbound Local Subnet
svchost.exe UDP 2177 Outbound, Inbound Local Subnet
system TCP 10244 Outbound, Inbound Local Subnet
ehshell.exe TCP 554 Outbound, Inbound Local Subnet
ehshell.exe UDP 5004, 5005 Outbound, Inbound Local Subnet
ehshell.exe TCP 8554-8558 Outbound, Inbound Local Subnet
ehshell.exe UDP 50004-50013 Outbound, Inbound Local Subnet
ehshell.exe UDP 7777-7781 Outbound, Inbound Local Subnet
mcrmgr.exe random Outbound Internet
mcx2prov.exe random Outbound Internet
svchost.exe random Outbound Local Subnet
ehrecvr.exe random Outbound Internet
ehrec.exe random Outbound Internet
ehexthost.exe random Outbound, Inbound Internet
mcupdate.exe random Outbound Internet
ehprivjob.exe UDP 5001-5006 Inbound Local Subnet
system TCP 2869 Outbound, Inbound Local Subnet
ehprivjob.exe UDP 5757-5772 Outbound Local Subnet