ACS discovery

ACS Discovery
There are several mechanisms a CPE can use to discover its associated ACS:

• Use locally configured URL of the ACS
The URL of ACS can be configured locally in the CPE. This method can be used
if a CPE is set to use a fixed IP address. The CPE can use DNS to resolve the IP
address of the ACS based upon the host name component of the URL. This
method shall be used only on initial connection to an ACS. After successfully
connecting to an ACS, this URL can be modified for subsequent connections.

• Use a DHCP [14] option
The URL of an ACS can be placed in a DHCP option. When the CPE gets its IP
address dynamically (via DHCP), it also receives the ACS URL in a DHCP
option. A common option to use is DHCP option 43, Vendor Specific Information A.1.
This option contains free text in which an ACS’ URL
information can be stored. TR-069 defines two relevant parameters - shown in
table below.
Since DHCP does not provide any security mechanism, configuration using a
DHCP option should be done via a secure link between the DHCP server and
CPE.

• Use stored ACS URL
Once a CPE has successfully established a connection with an ACS, it retrieves
the current ACS’s URL and stores it internally in the parameter:
ManagementServer.URL. The next connection to an ACS shall use the updated
ACSURL.

3가지 방법이 있어

1. CPE에 설정된 ACS URL을 이용하여 DNS를 통해 ACS의 IP주소를 찾는 방법. 이경우는 CPE의 IP가 고정되어있을때 사용해. 초기 연결에만 사용하고 그 이후의 연결은 CPE에 설정되어 있는 ACS URL을 수정한다음 수정된 ACS URL을 이용해

2. CPE의 IP주소를 가져오는 과정에서 DHCP 옵션 43에 저장되어 있는 ACS URL을 이용.

3. CPE가 ACS에 연결이 성립되었을때 현재 ACS의 URL을 ManagementServer.URL 변수에 저장하여 다음 연결에 저장된 ACS URL을 이용.