Port forwarding issue with SharePoint website and Exchange autodiscovery

Hi,

I have a SharePoint website which is hosted in my internal server ( App server ). The internal ip address is 10.x.x.213

I have used SSL certificate on the site. So I forwarded port on my Netgear router . Port 80 and Port 443 on the above server ip 10.x.x.213.  And I was able to access the site from outside typing domain . ( i.e https://sub.mydomain.com )

Then I installed Exchanged 2013 on different server with IP address 10.x.x.216 .

So the autodiscover for the exchange was installed on Port 443.

But I can't forward 443 again on the router for the exchange server 10.x.x.216 .

Could you please tell me how should I configure this to get  exchange ecp , owa and SharePoint website working from external.

If I forward 443 on 10.x.x.216 my exchange works fine from outside. Then my SharePoint website stop working.

I would appreciate your help and cooperation

Thanks

Sowel