Enhanced Survivable Remote Site Telephony (E-SRST)

Enhanced SRST (E-SRST) advantages over SRST:

• Automatic provisioning - it is integrated with CUCM and can be centrally configured/deployed from CUCM
• Automatic Synchronization - the Cisco Unified Messaging Gateway (required piece of hardware/software for E-SRST) synchronizes the configuration from the central site to the branch on a schedule. 
• Consistent Device Layout - phone displays, basic functions (extensions, soft-key templates, phone types, etc) are carried over in E-SRST.
• Full call control features during failover
•  Call forward no answer, call forward all, call forward busy
• Time of Day routing
• Class of Service restrictions for both incoming and outgoing
• Hunt Groups
• Call Park and Call Pickup

SRST advantages of Enhanced SRST (E-SRST):

• Lots cheaper
• No extra licenses required other than basic SRST licenses
• Unified Messaging Gateway not needed
• SIP SRST supported
• Who needs to pay the extra money to support call park/pickup, hunt groups, and TOD!?!

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