If you see the following error on outbound calls, you may be triggering our Loss Prevention measures:
X-Reason: Rejected - Loss limits exceeded for origin/destination/account combination
At Simwood we offer termination to almost every potential destination with as specific breakouts as possible to ensure that you are never charged more than you should be. We also strive to avoid the need to pass along any origin surcharges* we receive from downstream.
When sending traffic to other carriers we will always try to absorb loss making traffic, up to a limit, for our customers. When this limit is breached, we may begin to reject some traffic. Should you see call rejections with the 'X-Reason: Rejected - Loss limits exceeded for origin/destination/account combination' we advise reviewing the traffic you are sending us, as well as reviewing the origin CLI of the affected calls as the more exotic the CLI is, the more likely it is to attract surcharges.
We have written a number of blogs on the matter and are committed to providing you as transparent and fair service as possible.
Unfortunately, our rates are sometimes a bit too good for certain combinations of breakout and CLI. We may be getting charged a significant amount for calls being passed downstream and the rates we are providing our customers could be far lower for that breakout. When this is the case, we may need to start rejecting calls in order to prevent loss making traffic from transiting our network. This traffic could be the result of legitimate traffic profiles for our customers or be due to customers having multiple carriers and utilising a predatory LCR****.
If you do see this error, please look into the traffic you are sending us and ensure that it has a good amount of UK CLI mixed in and remember that you can always allocate UK geographic and non-geographic numbers to your customers for outbound use.
The default SIP response code for these calls is a 603, however this can be changed upon request via email to our Support team.
*Origin Surcharges - Surcharges of up to £2 Per Minute for calls to any destination that have certain CLI** or Network Numbers***
**CLI - Calling Line Identification or presentation number
***Network Number - This is an underlying phone number, required when any anonymous call is used but can also be sent alongside any call with a valid CLI.
****Least Cost Routing - a system whereby you aggregate prices across your suppliers and ensure that calls always use the cheapest route for each call and usually have failover options also.