CallHome feature is not anything new, it has been around for quite some time now.  I remember hearing about it when the Sup720 years ago.  Believe it or not, I never really bothered to configure it or really tinker with it as our corporate support contract is through a VAR and not direct with TAC.
Well, with our Nexus switches I figured it was time to take a good look at this feature and configure it for internal use as well as for connectivity to our VAR.  Since I am configuring this feature, figured it was a good time to blog on how to!
This excert is taking directly from Cisco’s website on what Smart CallHome is:
Cisco® Smart Call Home is an award-winning, embedded support feature available on a broad range of Cisco products. Smart Call Home enabled devices continuously perform proactive diagnostics on their own components to provide real-time alerts and remediation advice when an issue is detected.
So, without future ado, here is how to configure Smart CallHome on the Nexus 7000:
1. Enter configuration mode
     N7K2# conf t
     Enter configuration commands, one per line.  End with CNTL/Z.
    
2. Once in Configuration mode, enter the callhome configuraiton section
     N7K2(config)# callhome
    
3. The first thing that you should do is define a the system contact information.  This is the group or person(s) who are resposible for the system.  My suggestion is to first designate a small group of key individuals, fine-tune the features, and then deploy to a larger group, or preferrably, your Support Center (NOC)
     N7K2(config-callhome)# email-contact NexusSupportTeam@YourCompany.Com
     N7K2(config-callhome)# phone-contact +1-610-555-0542
     N7K2(config-callhome)# streetaddress 124 Colo Blvd, Colo City, Co 12345
     N7K2(config-callhome)# contract-id 12345
     N7K2(config-callhome)# site-id 2468
     N7K2(config-callhome)#  
  
4. Now, lets check the config via the SHOW CALLHOME
     N7K2(config-callhome)# show callhome
     callhome disabled
     Callhome Information:
     contact person name(sysContact):who@where
     contact person’s email:NexusSupportTeam@YourCompany.Com
     contact person’s phone number:+1-610-555-0542
     street addr:124 Colo Blvd, Colo City, Co 12345
     site id:2468
     customer id:
     contract id:12345
     switch priority:7
     duplicate message throttling : enabled
     periodic inventory : enabled
     periodic inventory time-period : 7 days
     periodic inventory timeofday : 08:00 (HH:MM)
     Distribution : Disabled
     N7K2-CoreSwitch2(config-callhome)#
5. Now we need to define a destination configuration. This is who the notifications will be sent to.  Again, this should be either a key group of people or your Support NOC.
     N7K2(config-callhome)# destination-profile Nexus-Support-NOC
     N7K2(config-callhome)# destination-profile Nexus-Support-NOC email-addr NexusSupport@YourCompany.Com
     N7K2(config-callhome)# destination-profile Nexus-Support-NOC format full-txt
     N7K2(config-callhome)# destination-profile Nexus-Support-NOC message-level 5
     N7K2(config-callhome)# destination-profile Nexus-Support-NOC alert-group all
     N7K2(config-callhome)#
6. To check to see what is now configured, execute the command show callhome destination-profile profile Nexus-Support-NOC
     N7K2(config-callhome)# show callhome destination-profile profile Nexus-Support-NOC
     Nexus-Support-NOC destination profile information
     maximum message size:2500000
     message format:full-txt
     message-level:5
     transport-method:email
     email addresses configured:
     NexusSupport@YourCompany.Com
     url addresses configured:
    
     alert groups configured:
     all
     N7K2(config-callhome)#
7. Now you will need to configure your SMTP server information
     N7K2(config-callhome)# transport email smtp-server 10.100.100.100 port 25 use-vrf default
     N7K2(config-callhome)# transport email from N7K2@YourCompany.Com
     N7K2(config-callhome)# transport email reply-to NexusSupportTeam@YourCompany.Com
    
8.  To check the configuration, use the show callhome transport-email command
     N7K2(config-callhome)# show callhome transport-email
     from email addr:N7K2@YourCompany.Com
     reply to email addr:NexusSupportTeam@YourCompany.Com
     smtp server:10.100.100.100
     smtp server port:25
    
9. Now all that is left to do is enable CallHome
     N7K2(config-callhome)# enable
    
10.To check the config, issue the show callhome command
     N7K2(config-callhome)# show callhome
     callhome enabled
     Callhome Information:
     contact person name(sysContact):who@where
     contact person’s email:NexusSupportTeam@YourCompany.Com
     contact person’s phone number:+1-610-555-0542
     street addr:124 Colo Blvd, Colo City, Co 12345
     site id:2468
     customer id:
     contract id:12345
     switch priority:7
     duplicate message throttling : enabled
     periodic inventory : enabled
     periodic inventory time-period : 7 days
     periodic inventory timeofday : 08:00 (HH:MM)
     Distribution : Disabled
     N7K2-CoreSwitch2(config-callhome)#
 I will post a seperate post on the Alert Groups.