However, when it comes to sending / receiving faxes, there’s a disconnect.  As much as VOIP has exploded in the past few years, surprisingly fax capabilities haven’t achieved much innovation.  I haven’t heard much talk around faxing in the cloud.  So far this is what I use…

There are 2 services that I use, both of which seem to be made in the pre-2000 era, but have maintained a sense of competitive edge over larger monthly subscription models (eFax.com, fax.com), etc.

	Why Cloud?	Why is it better?
	InterFAX maintains a developer API for service integration. Offers XML service (.NET, SOAP, WSDL), email gateway (SMTP) or ActiveX (COM objects). Fax directly from Outlook, email or web service. Manage your own CSID name.	I use this to send faxes for about $.11 / page.  Simply email a PDF attachment to [FAXNUMBER]@fax.tc.
	Easy faxing via email.  No per page charge or high monthly fees.  Just drop dead simple. Yes, there are other services that offer email-to-fax services, but Faxaway is the CHEAPEST and highly reliable.	Probably the cheapest and easiest way to send a fax. $1 monthly fee. $.11 per minute, not per page.

These are the two services out of about 20 that I checked with that offers flexible, cheap and simple ways to interface programmatically.  If you know of others, let me know.  I’m always looking for ways to make life more portable and efficient!

I have tested this with WordPress 2.7, hosted with Mosso, but I haven’t ran into this issue.  Searching the Wordpress Trac database yeilds no discussion.   However, there is an open ticket that’s up for grabs with a similar issue when dealing with proxy servers, which may be a growing issue with programming in the “cloud”.

Ticket #4602: Function for getting the clients IP address

WordPress misses a function to get the IP address of the original client. It is critical to have a function like this when using plugins for voting, users online and when posting comments whenWordPress runs on a server behind an HTTP proxy such as Varnish.

It checks if the header X-Forwarded-For is set (available from$_SERVER['HTTP_X_FORWARDED_FOR']) and uses the first address in this list. If it’s not set, it uses$_SERVER['REMOTE_ADDR'] instead.

The function also applies a filter called “remote_ip_address” before returning the address.

If you want a pluggable patch to this and are NOT using SSL use the patch from ticket #4602 mentioned above.

However, if you have SSL enabled for your domain you will need to replace the HTTP_X_CLUSTER_CLIENT_IP  with HTTP_X_FORWARDED_FOR.  This is because MOSSO uses a proxy for SLL, which builds a chain of client IP addresses in a comma delimited list.  The first IP address in this list. 

Here’s a quick function to get the client IP from a chained list:

if ($ip_address = $_SERVER["HTTP_X_FORWARDED_FOR"]) {
// IP addresses can be chained, separated with commas,
// we want the first one.
if (strpos($ip_address, ',') !== false) {
$ip_address = explode(',', $ip_address);
$ip_address = $ip_address[0];
}
}
else {
$ip_address = $_SERVER["REMOTE_ADDR"];
}


Someone should update the patch for ticket #4602 to reflect SSL support and verify this issue exists with other cloud networks.