Doc update: clarify guidelines for firewall setup.
Change-Id: Id3284bb21a0a2b612babf6cf582fda8f1c73cb80
diff --git a/docs/html/google/gcm/gcm.jd b/docs/html/google/gcm/gcm.jd
index fb57a91..26fc49a 100644
--- a/docs/html/google/gcm/gcm.jd
+++ b/docs/html/google/gcm/gcm.jd
@@ -777,10 +777,11 @@
<p class="note"><strong>Note:</strong> If your organization has a firewall
that restricts the traffic to or
-from the Internet, you need to configure it to allow connectivity with GCM.
+from the Internet, you need to configure it to allow connectivity with GCM in order for
+your Android devices to receive messages.
The ports to open are: 5228, 5229, and 5230. GCM typically only uses 5228, but
it sometimes uses 5229 and 5230. GCM doesn't provide specific IPs, so you should
-allow your server to accept incoming connections from all IP addresses
+allow your firewall to accept incoming connections from all IP addresses
contained in the IP blocks listed in Google's ASN of 15169.</p>