source of a message

Starting a few days ago, I see the following once in syslog:

2019-02-07T10:03:10.411207-08:00 vishnu smsbox[2075]: 2019-02-07 10:03:10 [2075] [5] INFO: Starting to service <#001#006'application/vnd.wap.mms-message> from <1111301000> to <1234>

Followed by many of these:
2019-02-07.gz:2019-02-07T10:05:10.583219-08:00 guru smsbox[2075]: 2019-02-07 10:05:10 [2075] [5] INFO: Starting to service <11121611611 Error Invalid Number. Please re-send using a valid 10 digit mobile number or valid short code. No service specified> from <+1121611611> to <1234>

What device submitted this message?  I don't see an IP address in these log lines


As far as I know, the only source of SMS messages to my Kannel installation is a script ('send-sms') which executes an HTTP PUT on the following URL:
  $url = "http://$gateway/cgi-bin/sendsms?username=$username&password=$password&to=$recipient_tel&text=$message";

And normally, I see something like the following in syslog:

2019-02-07T08:00:32.314355-08:00 guru smsbox[2075]: 2019-02-07 08:00:32 [2075] [3] INFO: smsbox: Got HTTP request </cgi-bin/sendsms> from <10.12.7.11>
2019-02-07T08:00:32.314415-08:00 guru smsbox[2075]: 2019-02-07 08:00:32 [2075] [3] INFO: sendsms used by <watcher>
2019-02-07T08:00:32.314472-08:00 guru smsbox[2075]: 2019-02-07 08:00:32 [2075] [3] INFO: sendsms sender:<watcher:12345> (10.12.7.11) to:<2069548415> msg:<Crier-->dn:1[console.aws.amazon.com]>

In other words, the only source for SMS messages is 10.12.7.11 ... what does the source 1111301000 mean ... it doesn't look like an IP address to me.

--sk