Most changes in Enswitch 3.6 purely add functionality, but some change or remove functionality. Here is a list of such changes. If any of these adversely affect you, please contact support as soon as possible.

• The dial plans code has been completely re-written. If using multiple dial plans, please test comprehensively on a test machine before upgrading.
• Zaptel is no longer supported. If still in use, please migrate to DAHDI.
• The "class of service exceptions" and "Routing exceptions" links on the edit rate plan page have been combined into a "Routes" link. Data should be migrated automatically, but it's recommended to review each rate plan after the upgrade. Unlike the old routing exceptions, the new routes need not match the exact system route used.
• The customer class of service exceptions under Features » Class of service are now in the customer's dial plan.
• The "maxmessage" and "minmessage" columns in the mailboxes table have been replaced by "maxsecs" and "minsecs", and the defaults for the new columns are now set in the System » Configuration menu rather than using SQL defaults. Field values will be migrated automatically, but if you've changed the SQL defaults please update the "Maximum mailbox duration" and "Minimum mailbox duration" configuration settings.
• The "Free internal calls" configuration setting has been replaced by a "Free internal calls" rate plan feature. This data will be migrated automatically, but if you've enabled this setting it's recommended to review this setting within each rate plan after the upgrade.
• Original callerids for telephone lines and remote access accounts should now be sent in the dial plan of the telephone line or remote access accounts. If you have customers using original callerid, please ask them to check their settings.
• <minimum_payment> and <due> elements have been added to the XML invoice template. If you have a custom version of this template, or have created XSLT for it, please update your code.
• Customers are emailed if their credit card payment failed.
• Page groups only allow one call at a time. The second caller will hear a busy tone. This can be changed by a configuration setting.
• Page groups no longer ring the calling telephone line if it's part of the page group. This can be changed by a configuration setting.
• As always, some SOAP API functions have changed. Please see /opt/enswitch/current/doc/api_changes.txt for a list.