WholesalePBX currently has proxy servers in four cities in the United States, close to regional peering points. For testing purposes, you may TRACEROUTE and PING to the following endpoints:
- ashburn.va.wpbx.net (Ashburn, VA)
- chicago.il.wpbx.net (Chicago)
- denver.co.wpbx.net (Denver)
- sanjose.ca.wpbx.net (San Jose, CA)
Please do not hard code these particular addresses into any device or softphone. Doing so will impair the automatic failover functionality built into our system.
WholesalePBX uses DNS SRV records as our primary method of failover. SRV records are similar to MX records in that they allow us to define multiple servers as well as the priority in which these servers should be used.
For example, normally when devices are provisioned on our system, they are assigned a proxy server of macaddress.proxy.wpbx.net, and this DNS record is prioritized based on the expected physical location of the device. For example, a device to be located in Los Angeles would be configured to use the San Jose server, followed by (in order of preference) Denver, Chicago, and Ashburn. A device in Chicago may be provisioned as Chicago, Ashburn, Denver, San Jose.
There are some devices, such as softphones and certain older Cisco equipment (7940, 7960) which are not auto-provisioned and are not going to have their own custom DNS entries. In these cases, we have set up two regional proxy addresses:
- east.proxy.wpbx.net
- west.proxy.wpbx.net
These addresses have two DNS entries, a standard A/CNAME record and a SRV record (note: SRV records are actually _sip._udp.east.proxy.wpbx.net, for example, but the prefixes are omitted for clarity). The main record is either an A or CNAME record pointing to one specific server. This record has a very short TTL (60 seconds) and in the event a server is taken offline, the record will be re-pointed automatically to the next machine. The SRV records have multiple servers defined in series.
