According to Google no incoming ports are required, as you'd expect (see link and quote below). The printer/server opens an XMPP+STARTTLS TCP connection to talk.google.com
, and Google notifies print jobs over that persistent connection. It is up to the printer/server to stay connected to talk.google.com
, and reconnect as needed. Reading the web there are many printers that do not achieve keeping that connection alive. Some fail whenever their DHCP assigned IP changes. Some fail when they wake up from power sleep modes and don't reconnect. Some fail because they just don't attempt to reconnect if the connection gets lost for any reason. Some like the Canon MX922 (firmware 3.01) I have here require you to manually reconnect from the menu every day.
I just read a ton of forum posts and many GCP certified printers have these problems. The GCP certification program don't not appear to pick up the inability to reliably maintain or reconnect the outward TCP connection to talk.google.com
. It appears to be poor vendor implementations of GCP that Google certification approves. A Google person also mentioned other implementation issues like not supporting security token lengths that GCP certification also doesn't pick up.
Reading the Internet I can give a general summary what printer owners have said - at least about consumer inkjet/laser printers.
- Canon: Completely broken GCP implementation(s), unable to maintain a connection, requires manual reconnection through the menu, usually at least daily
- Brother: Works if you assign fixed IP to the printer
- HP: Works because it uses ePrint -> GCP rather than GCP on the printer
- Epson: Only recent printers support GCP, but apparently they do work, e.g. XP 410 given a positive review for this issue
I've yet to own a GCP printer that works reliably :-(. In my experience HP printers do work because they don't use GCP on the printer, they use HP ePrint to HP servers, which in turn connect to GCP. Maybe I'll try that Epson next!
You could blame the vendors for their implementation, but then what is Google GCP certification for if not to identify bad implementations?
> Is Port 5222 required inbound for the print server?
No, only 5222 outbound is required.
443 TCP (HTTPS), with connections to:
5222 TCP (XMPP, using STARTTLS), with a persistent connection to: