Calling South Sudan from the United States explained:

• 011 - US exit code; dial first for international calls made from the USA or Canada
• 211 - Country Code for South Sudan
• Phone Number - 9 digits
• US to South Sudan international dialing format: 011 211 ???? ?????

How to dial to South Sudan cellular:

• dialing format for calls to a cell phone: 011 211 9??? ?????

Phone Books:

• Juba Travel Guide - publishes helpful information and contacts