If you wish to use version 2c or 3, use the following functions:
snmp v2c functions:
snmp2_get (string host, string community, string object_id [, int timeout [, int retries]])
snmp2_getnext (string host, string community, string object_id [, int timeout [, int retries]])
snmp2_walk (string host, string community, string object_id [, int timeout [, int retries]])
snmp2_real_walk (string host, string community, string object_id [, int timeout [, int retries]])
snmp2_set (string host, string community, string object_id, string type, mixed value [, int timeout [, int retries]])
snmp v3 functions:
snmp3_get (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string priv_pr)
snmp3_getnext (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string pri)
snmp3_walk (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string priv_p)
snmp3_real_walk (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string p)
snmp3_set (string host, string sec_name, string sec_level, string auth_protocol, string auth_passphrase, string priv_pr)