Routit is a Dutch ISP which does not only offer Internetconnectivity for businesses they also offer hosted telephony and SIP-trunks. Although this is a Dutch ISP, their hostingplatform is an international one; Broadworks by Broadsoft. At the moment they are at version 19 I believe.
I already have experience with their hosted products but configuring a Routit SIP-trunk on a Cisco Unified Communication Manager Express (short CME) was new for me (not the SIP-trunk itself but connecting it with Routit).
Everytime I have to configure a SIP-trunk for an ISP I haven't worked with it always take time to discover what it takes to get it working. In this case I haven't even looked at the tunable SIP-parameters and options but only at the authentication. The ISP didn't have any real examples available for setting things up on a CME (or UC500) only a snippet of a sip-ua config once sent to them by another partner.
It took me some time to get the authentication right (and some cursing etc. :-))
