Do you mean -

Cisco Certified Network Associate in Service Provider Operations (CCNA SP Operations) 640-760 SSPO
or
Cisco Certified Network Associate - Service Provider (CCNA SP) 640-875 SPNGN1 & 640-878 SPNGN2

The first you need a CCNA, the second one there is no prerequisite.
If you look at the 640-875 SPNGN1 it covers most of the CCNA anyhow?