We purchase a c2821 with srst. I recieve the router , it has a c2800-nm-spservicesk9-mz.124-21.bin image.
is the srst included?, what version is?.
where download the latest srst version?.
Your router with c2800-nm-spservicesk9-mz.124-21.bin seems include
SRST: Survivable Remote Site Telephony Version 3.0
You can download the last ios version on the cisco web site.
Hope this help you.