Siemens SIMATIC NET TeleControl S7-1200 CP 1243-1 Operating Instructions Manual page 16

Application and properties
1.5 Configuration limits and performance data
Frame memory (send buffer)
The CP has a frame memory (send buffer) for the values of data points configured as an
event.
The send buffer has a maximum size of 64000 events divided into equal parts for all
configured communications partners. The size of the frame memory can be set in STEP 7,
refer to the section SNMP (Page 42).
Messages / e-mail
Up to 10 messages can be configured in STEP 7 and sent as e-mails.
IPsec tunnel (VPN)
Up to 8 IPsec terminals can be established for secure communication with other security
modules.
Firewall rules
The maximum number of firewall rules in advanced firewall mode is limited to 256.
The firewall rules are divided up as follows:
● Maximum 226 rules with individual addresses
● Maximum 30 rules with address ranges or network addresses
(e.g. 140.90.120.1 - 140.90.120.20 or 140.90.120.0/16)
● Maximum 128 rules with limitation of the transmission speed ("Bandwidth limitation")
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Operating Instructions, 12/2016, C79000-G8976-C365-02
CP 1243-1