I would love to see a competitive alternative to RadUSA’s TDMoIP SFP gateways that ar $800+. You make fiber SFPs… How about showing TDMoIP some love. 
+1 for this!
contact RMCTel (info at rmctel dot sk). they have cheaper alternatives both for E1, STM1 and STM4.
also they have stuff that can do ACR (adaptive clock recovery) which does not require Synchronous Ethernet
support (something what’s hw specific and Mikrotik does not support).