[VoiceOps] Looking for cost-effective eSBC that supports inband DTMF <-> RFC2833 transcoding support

[Frank Bulk]

We have an educational customer with an IVR that only supports RFC 2833 and
an eSBC (Mitel border gateway) that cannot not perform transcoding from
inband DTMF to RFC2833.  There are some local VoIP to VoIP calls where the
caller's device only supports inband DTMF and our softswitch cannot
transcode them, so the IVR doesn't work for some parents and constituents.

We'd like to recommend a cost-effective eSBC that supports inband DTMF <->
RFC2833 transcoding.  

Any recommendations from this group?  I looked at EdgeMarc, but apparently
their newer models don't have a DSP, or at least that functionality,
anymore.

Frank