https://www.informit.com/articles/article.aspx?p=2492950&seqNum=4
SRST and E-SRST Configuration | Remote Site Telephony and Branch Redundancy Options | InformIT
Hannah and Behl introduce and explain the various options for deploying remote site telephony solutions.
e configurationremote sitesrst
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/15-2_2_e/configuration/guide/b_1522e_2960_2960c_2960s_2960sf_2960p_cg/m_1522e_layer2_optional_spanning_tree_2960_2960s_cg.html
Software Configuration Guide, Cisco IOS Release 15.2(2)E (Catalyst 2960, 2960-S, 2960-SF and...
Configuring Optional Spanning-Tree Features
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/15-2_2_e/configuration/guide/b_1522e_2960_2960c_2960s_2960sf_2960p_cg/m_1522e_layer2_flex_link_2960_2960s_cg.html
Software Configuration Guide, Cisco IOS Release 15.2(2)E (Catalyst 2960, 2960-S, 2960-SF and...
Configuring Flex Links and the MAC Address-Table Move Update Feature