Subject: [dhcwg] Reminder - WGLC for draft-ietf-dhc-access-network-identifier-02 - respond by April 27, 2014

From: Hidetoshi Yokota <[email-masked]>
Date: Sat, 26 Apr 2014 16:53:56 +0900

Dear all,

I reviewed the I-D and think it is in good shape for
publication. Maybe one more cycle of revision would be
beneficial. I add my comments below, most of which are for
clarification.

===================

4. DHCPv4 Access-Network-Identifier Option

Access network identifier option carries information to identify the
access network to which the client is attached to. This information
includes access technology type, network identifier and access
network operator identifiers.

The format of the DHCPv4 Access-Network-Identifier option is shown
below.

Code Len ANI Sub-options
+------+------+------+------+------+-- --+-----+
| code | len | s1 | s2 | s2 | ... | sn |
+------+------+------+------+------+-- --+-----+

code: 8-bit code carrying Access Network Identifier sub-options,
If added by relay agent: Relay Agent Information Option (82)
If added by client: OPTION_ACCESS_NETWORK_ID (TBD1)

[HY] It should be resolved which option to be used (82 or TBD1) at this point.

len: 8 bit indicating total length of the included suboptions.

[HY] The following sub-option format should go into Section 4.1

ANI Sub-options: The ANI Sub-options consists of a
sequence of SubOpt/Length/Value tuples for each sub-option, encoded
in the following manner:

SubOpt Len Sub-option Value
+------+------+------+------+------+------+--...-+------+
| code | N | s1 | s2 | s3 | s4 | | sN |
+------+------+------+------+------+------+--...-+------+

ANI Sub-options are defined in following sections.

4.1. DHCPv4 Access-Network-Identifier Sub-options

Access network identifier information will be defined in multiple
sub-options. The initial assignment of DHCP access network
identifier Sub-options is as follows:

Bhandari, et al. Expires August 17, 2014 [Page 5]

Internet-Draft DHCPv4 & v6 ANI options February 2014

Sub-option Code Sub-Option Description
--------------- ----------------------
TBD7 Access-Network-Type Sub-option
TBD8 Network-Name Sub-option
TBD9 AP-Name Sub-option
TBD12 AP-BSSID Sub-option
TBD10 Operator-Identifier Sub-option
TBD11 Operator-Realm Sub-option

5. DHCPv6 Access-Network-Identifier options

The Access Network Identifier option defined here will be added by
DHCPv6 client in upstream DHCPv6 messages or by the Relay in Relay-
forward messages.

Option Code Descrption
--------------- ----------------------
TBD2 OPTION_ANI_ATT
TBD3 OPTION_ANI_NETWORK_NAME
TBD4 OPTION_ANI_AP_NAME
TBD13 OPTION_ANI_AP_BSSID
TBD5 OPTION_ANI_OPERATOR_ID
TBD6 OPTION_ANI_OPERATOR_REALM

6. DHCPv4 and DHCPv6 Access-Network-Identifier Options

This section defines DHCPv4 suboption and DHCPv6 options for access
network identification.

6.1. Access-Network-Type option

[HY] Access-Network-Type (Sub-)option [Sub-option for DHCPv4, Option for DHCPv6]

This option is used for exchanging the type of the access technology
the client is attached to the network. Its format is as follows:

Bhandari, et al. Expires August 17, 2014 [Page 6]

Internet-Draft DHCPv4 & v6 ANI options February 2014

DHCPv4:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboption-code| Length | ATT |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

suboption-code: 8-bit code, it should be set to value of (TBD7),
indicating that its a Access-Network-Type sub-option

Length: 8-bit unsigned integer indicating the length of this suboption
in octets, excluding the suboption-code and length fields.
This field MUST be set to 2.

[HY] According to RFC5213, the length of ATT is 1 octet. if 2 octets is preferred, 1 octet of reserved field should be prepended.

DHCPv6:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Code (TBD2) | OptLen |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ATT +
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

option-code: 16-bit code OPTION_ANI_ATT (TBD2)
option-length: 16-bit unsigned integer indicating length
in octets of this option

[HY] It should be specified which value to be set in oOptLen and the same argument as the above.

Common format applicable to DHCPv4 and DHCPv6:
Access Technology Type (ATT)

An 16-bit field that specifies the access technology through
which the client is connected to the access link.

The values is as populated from the IANA name space
Access Technology Type Option type values as requested in [RFC5213]

0: Reserved ("Reserved")
1: Virtual ("Logical Network Interface")
2: PPP ("Point-to-Point Protocol")
3: IEEE 802.3 ("Ethernet")
4: IEEE 802.11a/b/g ("Wireless LAN")
5: IEEE 802.16e ("WIMAX")

[HY] IANA assigns more than these values (0-12). Refer to the following link:
http://www.iana.org/assignments/mobility-parameters/mobility-parameters.xhtml#mobility-parameters-10

Bhandari, et al. Expires August 17, 2014 [Page 7]

Internet-Draft DHCPv4 & v6 ANI options February 2014

6.2. Network-Identifier options

[HY] Network-Identifier (Sub-)options
Note: "(Sub-)options for Network identifier" may be better for a general name.

These options can be used for carrying the name of the access network
(e.g., a SSID in case of IEEE 802.11 Access Network, or PLMN
Identifier [TS23003] in case of 3GPP access ) and Access Point name,
to which the client is attached. The format of these options is
defined below.

DHCPv4:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|suboption code | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Name (e.g., SSID or PLMNID) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

suboption code: 8-bit code, it should be set to value of (TBD8),
indicating that its a Network-Name sub-option

Length: 8-bit indicating Total length of this sub option,
excluding the suboption code and length fields.
The value can be in the range of 2 to 32 octets.

[HY] "Total length" is misleading since this does not include the subopt code and length fields. I recommend "the length" instead.

DHCPv6:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Code (TBD3) | OptLen |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Name (e.g., SSID or PLMNID) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

option-code: 16-bit code OPTION_ANI_NETWORK_NAME (TBD3)
option-length: 16-bit unsigned integer indicating length
in octets of this option.The value can be in the
range of 2 to 32 octets.

Common format applicable to DHCPv4 and DHCPv6:

Network Name: The name of the access network to which the mobile

Bhandari, et al. Expires August 17, 2014 [Page 8]

Internet-Draft DHCPv4 & v6 ANI options February 2014

node is attached. The type of the Network Name is dependent on
the access technology to which the mobile node is attached. If it
is 802.11 access, the Network Name MUST be the SSID of the
network. If the access network is 3GPP access, the Network Name
is the PLMN Identifier of the network. If the access network is
3GPP2 access, the Network Name is the
Access Network Identifier [ANI].

When encoding the PLMN Identifier, both the Mobile Network Code
(MNC) [TS23003] and Mobile Country Code (MCC) [TS23003] MUST be 3
digits. If the MNC in use only has 2 digits, then it MUST be
preceded with a '0'. Encoding MUST be UTF-8.

Bhandari, et al. Expires August 17, 2014 [Page 9]

Internet-Draft DHCPv4 & v6 ANI options February 2014

DHCPv4:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|suboption code | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access-Point Name ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

suboption code: 8-bit code, it should be set to value of (TBD9),
indicating that its a Network-AP-Name sub-option

[HY] "Network-AP-Name sub-option" -> "AP-Name Sub-option".

Length: 8-bit indicating Total length of this sub option,
excluding the suboption code and length fields.
The value can be in the range of 2 to 32 octets.

[HY] Same argument for "Total length".

DHCPv6:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Code (TBD3) | OptLen |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access-Point Name ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

option-code: 16-bit code OPTION_ANI_AP_NAME (TBD4)
option-length: 16-bit unsigned integer indicating length
in octets of this option.The value can be in the
range of 2 to 32 octets.

Common format applicable to DHCPv4 and DHCPv6:

Access-Point Name: The name of the access point (physical device
name) to which the mobile node is attached. This is the
identifier that uniquely identifies the access point. While
Network Name (e.g., SSID) identifies the operator's access
network, Access-Point Name identifies a specific network device in
the network to which the mobile node is attached. In some
deployments, the Access-Point Name can be set to the Media Access
Control (MAC) address of the device or some unique identifier that
can be used by the policy systems in the operator network to
unambiguously identify the device. The string is carried in UTF-8
representation.

[HY] 3GPP also defines "Access Point Name (APN)" as a reference to GGSN/PGW according to [TS23003]. This should be disambiguated.

Bhandari, et al. Expires August 17, 2014 [Page 10]

Internet-Draft DHCPv4 & v6 ANI options February 2014

DHCPv4:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|suboption code | Length(6) | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Access-Point BSSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

suboption code: 8-bit code, it should be set to value of (TBD12),
indicating that its a AP-BSSID sub-option

Length: 8-bit indicating Total length of this sub option,
excluding the suboption code and length fields.
The value is set to 6.

[HY] Same argument for "Total length".

DHCPv6:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Code (TBD3) | OptLen(6) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access-Point BSSID ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code: 16-bit code OPTION_ANI_AP_BSSID (TBD13)
option-length: 16-bit unsigned integer indicating length
in octets of this option.The value is set to 6.

Common format applicable to DHCPv4 and DHCPv6:

Access-Point BSSID: The 48-bit Basic service set identification(BSSID)
of the access point to which the mobile node is attached.

6.3. Operator identifier options

[HY] "Operator-Identifier (Sub-)option

The Operator identifier options can be used for carrying the operator
identifier of the access network to which the client is attached.

[HY] The Vendor-specific suboption for Relay agent option [RFC4243] can carry the same type of information. Any thought on that?

The format of these options is defined below.

Bhandari, et al. Expires August 17, 2014 [Page 11]

Internet-Draft DHCPv4 & v6 ANI options February 2014

DHCPv4:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboptioncode | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Operator Enterprise ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

suboption code: 8 bit code, It should be set to value of (TBD10),
indicating that it is Operator-Identifier sub-option

Length: Total length of this sub option, excluding the suboption code
and length fields.

[HY] 8 bit of length? Also, the same argument for "Total length". The value can be fixed to "32".

DHCPv6:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Code (TBD4) | OptLen |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Operator Enterprise ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

option-code: 16-bit code OPTION_ANI_OPERATOR_ID (TBD5)
option-length: 16-bit unsigned integer indicating length
in octets of this option.

[HY] The Vendor-specific suboption for Relay agent option [RFC4243] can carry the same type of information. Any thought on that?

The format of these options is defined below.

Bhandari, et al. Expires August 17, 2014 [Page 11]

Internet-Draft DHCPv4 & v6 ANI options February 2014

DHCPv4:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboptioncode | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Operator Enterprise ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

suboption code: 8 bit code, It should be set to value of (TBD10),
indicating that it is Operator-Identifier sub-option

Length: Total length of this sub option, excluding the suboption code
and length fields.

[HY] The value can be fixed to "32".

Common format applicable to DHCPv4 and DHCPv6:

Operator Enterprise ID: Vendor ID as a four octet
Private Enterprise Number [SMI].

Bhandari, et al. Expires August 17, 2014 [Page 12]

Internet-Draft DHCPv4 & v6 ANI options February 2014

DHCPv4:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboptioncode | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Operator Realm ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

suboption code: 8 bit code, It should be set to value of (TBD11),
indicating that it is Operator-Realm sub-option

Length: Total length of this sub option, excluding the suboption
code and length fields.
[HY] The Vendor-specific suboption for Relay agent option [RFC4243] can carry the same type of information. Any thought on that?

The format of these options is defined below.

Bhandari, et al. Expires August 17, 2014 [Page 11]

Internet-Draft DHCPv4 & v6 ANI options February 2014

DHCPv4:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboptioncode | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Operator Enterprise ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

suboption code: 8 bit code, It should be set to value of (TBD10),
indicating that it is Operator-Identifier sub-option

Length: Total length of this sub option, excluding the suboption code
and length fields.

[HY] 8 bit of length? Also, the same argument for "Total length".

DHCPv6:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Code (TBD4) | OptLen |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Operator Realm ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

option-code: 16-bit code OPTION_ANI_OPERATOR_REALM (TBD6)
option-length: 16-bit unsigned integer indicating length
in octets of this option.

Common format applicable to DHCPv4 and DHCPv6:

Operator Realm: Realm of the operator. Realm names are required to be
unique, and are piggybacked on the administration of the DNS
namespace. Realms are encoded using a domain name encoding
defined in [RFC1035].Up to 253 octets of the operator realm.

[HY] According to RFC1035, the maximum length of a domain name is 255. if it has more than 253, is it truncated? If so, how?

13. Change log

Changes from 00 - 01

[HY] Changes from 01 - 02 ?

o Added AP BSSID information

Changes from 00 - 01

o Edited security consideration to handle multiple relay agents
adding access network identifier options, server and relay agent
behavior.

===================

--
Hidetoshi Yokota

KDDI R&D Laboratories, Inc.
e-mail:[email-masked]