We uniquely support the ability to further control your outbound calls by use of custom SIP headers.
Service Scope
Simwood SIP Termination is provided as a wholesale service to service providers only, this is not suitable for end users.
This document should be read in conjunction with our Outbound SIP Interop Information
If using any custom headers please ensure you test your implementation fully before relying on them. If you are unsure as to whether the headers are being sent correctly please contact Support.
X-simwood-tag
Outbound Reconciliation
This should be a short alphanumeric string being careful to avoid control characters or making it too long, either of which could cause validation issues in your own network or at the Simwood edge.
It is intended to carry an account code or your own internal reference for the call to enable reconciliation or onward billing.
Example use;
X-simwood-tag: ACC012345 X-simwood-tag: ACMEWidgets
X-simwood-maxcpm
Outbound cost limitation
This header can be used to limit the maximum cost per minute of an outbound call.
The value must be greater than zero and expressed in decimal form and in your billing currency (e.g. EUR, GBP or USD as appropriate).
This is intended for fraud prevention and where you wish to offer services to a customer which are being paid for by inbound revenue share (e.g. if your inbound revenue is 3p/min you may not want to offer forwarding to a number with a higher cost than this)
By default where a max cost per minute is set any destination with a non-zero connection charge will be rejected, even if the cost per minute is below the threshold set. This behaviour can be altered with the X-simwood-maxcpc header below
NB This feature is provided on a 'best efforts' basis, whilst we believe it's an effective addition it is not a replacement for existing fraud prevention measures and we must reiterate that all traffic initiated over your SIP trunk is your responsibility.
Example use (request call to be limited to 5p/min);
X-simwood-maxcpm: 0.05
If a call is rejected you received a SIP 403 Forbidden response with the following explanatory header;
X-Reason: Call to 447790900123 will exceed 0.001 ( 0.01200 )
X-simwood-maxcpc
Outbound connection cost limitation
This must be used in conjunction with a non-zero X-simwood-maxcpm header.
Where a destination has a non-zero connection charge associated with it and a limit on the cost per minute is set the call will not complete, as the connection charge could exceed the cost per minute. This behaviour can be changed with the X-simwood-maxcpc header.
Example use (request call to be limited to 5p/min, but allow calls with up to a 10p connection charge);
X-simwood-maxcpm: 0.05
X-simwood-maxcpc: 0.10
If a call is rejected you received a SIP 403 Forbidden response with the following explanatory header;
X-Reason: Call to 449098790000 will exceed 0.10 ( 0.4500 )
X-simwood-maxcost
Outbound total call cost limitation
Maximum cost of a call, specified in your account currency. Unlike the above maxcpc and maxcpm options, this is not considered at the start of a call but instead implements a limit on the maximum cost of the call, when this cost is exceeded the call will be automatically cleared by Simwood.
Example use (request call to be limited to £3.00);
X-simwood-maxcost: 3.00
NB: Please note that this is an approximation, and there is a possibility that calls will exceed the specified limit by a small amount, and is intended for fraud prevention and revenue protection, not accurate credit control purposes.
X-simwood-maxdur
Outbound call duration limitation
Maximum duration of a call in seconds. Much like maxcost above, this implements a limit on the maximum duration of the call, when this duration is reached the call will be automatically cleared by Simwood.
Example use (limit call to 1 hour);
X-simwood-maxdur: 3600
Security Considerations
As X-simwood headers can modify the behaviour of your account we would strongly recommend you filter any such headers that may be sent by your customers' equipment before passing the calls to the Simwood network.
We would also suggest that you ensure X-simwood headers are only sent on calls to the Simwood network.
Fragmentation
Care should be taken when using the above, especially X-simwood-tag, not to exceed 1400 bytes or packet fragmentation may occur. Ideally you should use TCP for your SIP Signalling (all our platforms support TCP and TLS) to avoid this.
Custom Reply Headers
We may include headers prefixed with X-simwood, as well as the X-Reason header, in our SIP messages to you.
You should ensure that you strip any X-simwood or X-Reason headers before passing SIP messages back to your customers' equipment as in the future these headers may be used to expose information about your account (e.g. tariff data / rates)
X-Reason
Note that the format of the X-Reason and X-simwood-reason header messages are subject to change without notice, they are intended to be human-readable messages to help assist in fault-finding and are not suitable to be relied upon for automated parsing.
Further information
More information can be found in the attached document.
Comments
0 comments
Article is closed for comments.