Enable SIP2 in Koha. How to configure SIP server in Koha 18.11??

First to enable the SIP2, run the commands below:

#koha-enable-sip library      [where library is the koha instance name]
#koha-start-sip library          [start the sip server]
#koha-stop-sip library          [stop the sip server]

Next, configure the SIPconfig.xml

#vim /etc/koha/sites/library/SIPconfig.xml

Add the necessary details in the SIPconfig.xml file

<acsconfig xmlns="http://openncip.org/acs-config/1.0/">
<!-- above address gets nothing, it's just a namespace -->
  <error-detect enabled="true" />
<!--  Set Net::Server::PreFork runtime parameters  syslog_ident will identify SIP2 Koha server entries in syslog  For OpenSolaris, add: syslog_logsock=stream--> 

<server-params    
       min_servers='1'    
      min_spare_servers='0'   
      log_file='Sys::Syslog'   
      syslog_ident='koha_sip'  
      syslog_facility='local6'  
/> 
<listeners>
<!-- vestigial HTTP, never implemented: just use the OPAC!  
 <service     
 port="0:8080/tcp"     
 transport="http"      
protocol="NCIP/1.0" />
-->    
<service      
port="8023/tcp"     
 transport="telnet"     
 protocol="SIP/2.00"     
 timeout="60" />    

<service      
port="220.158.236.188:6001/tcp"   <!-- Replace with your Koha server IP Address-->     
 transport="RAW"     
 protocol="SIP/2.00"     
 client_timeout="600"     
 timeout="60" />
<!--- client_timeout times out active connections which have not received     input from the client. Many persistent connections will send a status request     every 5-7 mins so setting this to less than that will add instability to the connection     if explicitly set to zero, no timeout is applied to the connection.     NB the parameter timeout applies to the login process only and should be set to a lower value     to time out failed connections--> 

 </listeners>

  <accounts>     
 <login id="term1"  password="Term1" delimiter="|" error-detect="enabled" institution="JNEC" encoding="ascii" checked_in_ok="1" />      
<login id="koha"   password="koha"  delimiter="|" error-detect="enabled" institution="kohalibrary" encoding="utf8" />      
<login id="koha2"  password="koha" institution="kohalibrary2" terminator="CR" />      <login id="lpl-sc" password="1234" institution="LPL" />     
 <login id="lpl-sc-beacock" password="xyzzy"             
delimiter="|" error-detect="enabled" institution="LPL"             send_patron_home_library_in_af="1"             av_field_template="[% accountline.description %] [% accountline.amountoutstanding | format('%.2f') %]" >         
 <screen_msg_regex find="Greetings from Koha." replace="Welcome to your library!" />          
<screen_msg_regex find="Invalid patron barcode." replace="Barcode not found, are you sure this is your library card?" />      
</login>  
</accounts>
<!--Institution tags are for enabled branches.  There needs to be oneinstitution stanza for each institution named in the accounts above.The implementation attribute is actually used to find the code to run,in our case "ILS".-->

<institutions>    
<institution id="JNEC" implementation="ILS" parms="">          <policy checkin="true" renewal="true" checkout="true"            status_update="false" offline="false"          timeout="100"            retries="5" />  
  </institution>    

<institution id="MAIN" implementation="ILS" parms="">          <policy checkin="true" renewal="true" checkout="true"            status_update="false" offline="false"          timeout="100"            retries="5" />   
 </institution>   

 <institution id="CPL" implementation="ILS" parms="">          <policy checkin="true" renewal="true" checkout="true"            status_update="false" offline="false"          timeout="25" status_update="false" offline="false"          timeout="25"            retries="5" />    </institution>  

  <institution id="kohalibrary" implementation="ILS" parms="">          <policy checkin="true" renewal="false" checkout="true"            status_update="false" offline="false"          timeout="100"            retries="5" />   
 </institution>    

<institution id="kohalibrary2" implementation="ILS" parms="">          <policy checkin="true" renewal="false" checkout="true"          timeout="100"            retries="3" />    </institution>    <institution id="LPL" implementation="ILS">          <policy checkin="true" renewal="false" checkout="true"          timeout="100"            retries="5" />   
 </institution>
</institutions>
</acsconfig>

Before editing SIPconfig.xml file make sure you have created a patron in the Koha system with following details:

Patron Name: term1
Patron Password: Term1
Patron Privileges: Circulation 

After setting up SIPconfig.xml stop the SIP2 once and start the SIP2 to again:

#koha-stop-sip library          [stop the sip server]
#koha-start-sip library          [start the sip server]

Check the log file to see if the connection to SIP2 server is successful:

#sudo tail -f /var/log/syslog | grep koha_sip

If the connection fails, try disabling the filewall in the system:
# sudo ufw disable [for Ubuntu]
#sudo ufw status