Cisco “XM” line of AS5X servers (AS5350XM and AS5400XM) have been touted as major steps up in providing IP-to-IP transcoding, sometimes referred to as ‘softswitch’ functionality. The term softswitch denotes voice/video/data processing entirely on an IP basis – it completely avoids taking or handing off traffic to the phone system or to digital or analog phone lines.
Enterprising service providers can make use of ‘last generation’ technology, however. So while there are many excellent reasons for considering an XM platform, the fact is – there are ways to achieve many of the same results in other ways.
A clever workaround is to put a pair of AS5350s or AS5400s back to back, connected via a DS3 card (AS54-DFC-CT3). Traffic comes in and goes out on either gateway via Ethernet, and then is routed through the DS3 circuit to the 2nd gateway (in either direction) which sees the traffic then as having originated from a trunk line and happily obliges the transcoding operation.
Providers considering this approach need to remember that certain limitation still apply – mainly that (1) Cisco’s support for the product may have ended (although there are lots of alternatives to this) and (2) Cisco software support may have ended – with the AS5400 that means no IOS 15 (although 12.4 should be quite sufficient for most purposes).
Not a solution for all, but certainly worth considering.