Full pack of params available for applying to modem is shown below:

svc=admin/modems&params={"callMode":"create",
			"n":<text>,
			"ph":<text>,
			"ri":<uint>,
			"pr":<byte>,
			"pd":<text>,
			"f":<uint>,
			"cfg":{
			     ...
			},
			"un": [
				<long>,
				...
			      ],
			"bp": [
				<long>,
				...
			      ]
			}

{
	"id": <long>,	/* modem id */
	"n": <text>,	/* name */
	"ph": <text>,	/* phone number */
	"ri": <uint>,	/* restart interval */
	"pr": <byte>,	/* priority */
	"pd": <text>,	/* preferred destinations */
	"f": <uint>,	/* modem flags */
	"e": <bool>.	/* state: 0 - off, 1 - on */
	"cfg": 
		{
			"addon_cmds": <text>,		/* Additional initialization AT commands */
			"baudrate": <text>,		/* port speed */
			"data_only": <text>,		/* Use 8-bit encoding only */
			"factory": <text>,		/* modem type */
			"log_facility": <text>,		/* log file path */
			"phones_filter": <text>,	/* phones mask */
			"port": <text>,			/* serial port */
			"sms_retry_count": <text>,	/* SMS retry count */
			"smssc": <text>			/* SMS service center */
		},
	"un": [
		<long>,		/* unit id */
		...
	],
	"bp": [
		<long>,		/* billing plan id */
		...
	]
}