Subject: [Mipshop] AD review of draft-ohba-802dot21-basic-schema

From: Jari Arkko <[email-masked]>
Date: Fri, 26 Sep 2008 13:32:43 +0300

This was submitted as an individual submission for informational RFC. I 
have made my AD review on it. My detailed comments and questions are 
below. Overall, I think it is a good idea to document this type of a 
schema, and we are certainly happy to do so when the IEEE wants us to. 
However, the current draft version is not at all self contained and its 
very hard to understand what the different information pieces should 
carry, if you want to know it in exact enough detail to actually 
implement something. I would suggest revising the draft one more time 
before we move forward by adding sufficient explanations in comments 
about the individual data items and their format, semantics and 
dependencies.

I will also have to find an RDF expert to review this from that 
perspective before we move forward. But I'm waiting for a doc revision 
before doing that, because I think that expert will have same issues 
that I had in understand what the document wants to do.

Issues:

>    A value of Operator Type:
>    0: GSM/UMTS
>    1: CDMA
>    2: REALM
>    3: ITU-T/TSB
>   

This is underspecified. I do not know what kind of value to fill when 
the type is any of these values. Please specify the format.

> <owl:DatatypeProperty rdf:ID="ie_country_code">
>   <mihbasic:ie_identifier>0x10000003</mihbasic:ie_identifier>
>   <rdfs:domain rdf:resource="#NETWORK"/>
>   <rdfs:range rdf:resource="&xsd;string"/>
>  </owl:DatatypeProperty>
>   
Does this mean that you are using some string-based country names, e.g., 
"FI" or numeric E.164 country codes, e.g., 358? Please specify.

> <owl:Class rdf:ID="COST">
>   ...
>     <owl:onProperty rdf:resource="#cost_unit"/>
>     <owl:onProperty rdf:resource="#cost_value"/>
>     <owl:onProperty rdf:resource="#cost_curr"/>
>   

Can a cost entry appear multiple times? I'm trying to understand if this 
representation will allow different options, e.g., flat fee $20 or $1 
per minute. Then again, I'm not sure how the overall model of 802.21 
fits with payment options in the same way as in current web-based login 
model.

>    7: free
How is this different from, say, a flat rate with price of zero?

>    A three-letter currency code(e.g., "USD") specified by
>    ISO 4217.
>   
This should be a normative reference.

>    This class has properties that represent geographic coordinate.
>    The format is based on the Location Configuration Information (LCI)
>    defined in RFC 3825 <http://tools.ietf.org/html/rfc3825>.
>   
Another normative reference needed here. (And what does "based on" mean, 
exactly? Either you use that format or you need to define the format here.)
> <owl:ObjectProperty rdf:ID="min_pk_tx_delay">
>   
I wish there was an explanation somewhere what this and other class of 
service parameters can convey and what they cannot. The model seems 
relatively simple. The implication is that it cannot necessarily 
represent everything. For instance, packet transmit delay alone tells me 
very little without knowing what size packets we are talking about. And 
where's nominal bandwidth of the interface?

>  <owl:DatatypeProperty rdf:ID="regu_domain_country_code">
>   <rdfs:domain rdf:resource="#REGU_DOMAIN"/>
>   <rdfs:range rdf:resource="&xsd;String"/>
>  </owl:DatatypeProperty>
>   
Represented how?

>  <owl:DatatypeProperty rdf:ID="regu_class">
I did not understand what regu_class represents. Please specify. See 
also below.

>   <rdfs:comment>
Some of the objects have a comment, some don't. I was generally unable 
to understand the ones without. Please consider adding comments at least 
to all leaf object types.

>  <owl:DatatypeProperty rdf:ID="ie_net_frequency_bands">
I did not understand exactly what you wanted to represent here. Its an 
unsigned int, but in what units, hz, Mhz, etc? Is the frequency band 
indicates as in 900 - 910 Mhz, i.e., as two numbers or with one? Please 
specify in more detail.
>  <owl:DatatypeProperty rdf:ID="ip_cfg_mthds">
The options for this appear to be DHCP, FA, and access router. First of 
all, its unclear to me what access router means in this context. An 
access router can support any address configuration mechanism. Secondly, 
does this list exclude stateless address autoconfiguration?
>  <owl:DatatypeProperty rdf:ID="ie_net_supported_lcp">

What does LCP stand for in here?

>  <owl:ObjectProperty rdf:ID="ie_net_mob_mgmt_prot">
>   

Does this stand for *local* mobility management protocol, or something 
else? Note that networks do not have to be involved in other mobility 
management protocols. Or does this refer to the capability to handle 802.21?

>  <owl:ObjectProperty rdf:ID="ie_net_emserv_proxy">
>   
Proxy at what level?

>  <owl:DatatypeProperty rdf:ID="ie_net_mobile_network">
I think you mean a mobile network in the NEMO sense. If so, please 
clarify. "Mobile network" in the cellular terminology refers to a 
network that support mobile hosts.

>  <owl:ObjectProperty rdf:ID="ie_container_poa">
What is a POA?

> <owl:DatatypeProperty rdf:ID="mac_addr">
>   <rdfs:domain rdf:resource="#LINK_ADDR"/>
>   <rdfs:range rdf:resource="#TRANSPORT_ADDR"/>
>  </owl:DatatypeProperty>
>
>  <owl:Class rdf:ID="LINK_ADDR_3GPP_3G">
>   <rdfs:subClassOf rdf:resource="#LINK_ADDR"/>
>  </owl:Class>
>
>  <owl:DatatypeProperty rdf:ID="link_addr_3gpp_3g_cell_id_plmn_id">
>   <rdfs:domain rdf:resource="#LINK_ADDR_3GPP_3G"/>
>   <rdfs:range rdf:resource="&xsd;string"/>
>  </owl:DatatypeProperty>
>
>  <owl:DatatypeProperty rdf:ID="link_addr_3gpp_3g_cell_id_cell_id">
>   
First, you need references to the documents that define the PLMN and 
cell IDs and their format.s

Second, your model for 802 and 2/3G networks is very different. 2/3G 
cellular networks do not use link layer addresses in the same sense as 
they exist in Ethernet. Not sure we need to do anything about this, but 
I hope the authors realize that there are significant differences.

> <owl:DatatypeProperty rdf:ID="dcd_ucd_base_id">
>   <rdfs:domain rdf:resource="#DCD_UCD"/>
>   <rdfs:range rdf:resource="&xsd;unsignedShort"/>
>  </owl:DatatypeProperty>
>
>  <owl:DatatypeProperty rdf:ID="bandwidth">
>   <rdfs:domain rdf:resource="#DCD_UCD"/>
>   <rdfs:range rdf:resource="&xsd;unsignedShort"/>
>  </owl:DatatypeProperty>
>
>  <owl:DatatypeProperty rdf:ID="du_ctr_freq">
>   <rdfs:domain rdf:resource="#DCD_UCD"/>
>   <rdfs:range rdf:resource="&xsd;unsignedLong"/>
>  </owl:DatatypeProperty>
>
>  <owl:DatatypeProperty rdf:ID="eirp">
>   <rdfs:domain rdf:resource="#DCD_UCD"/>
>   <rdfs:range rdf:resource="&xsd;unsignedByte"/>
>  </owl:DatatypeProperty>
>
>  <owl:DatatypeProperty rdf:ID="ttg">
>   <rdfs:domain rdf:resource="#DCD_UCD"/>
>   <rdfs:range rdf:resource="&xsd;unsignedShort"/>
>  </owl:DatatypeProperty>
>
>  <owl:DatatypeProperty rdf:ID="rtg">
>   
Explanations needed for all of these.

>    RFC3588 <http://tools.ietf.org/html/rfc3588>. The first 2-octet contains AddressType, which may be
Reference needed.

>  <owl:Class rdf:ID="IP_SUBNET_INFO">

Can you send multiple subnet infos? IPv6 supports multiple prefixes.

And what if the subnet information is dependent on whatever happens in 
the network attachment phase. Proxy MIP, for instance, can choose the 
prefix based on random selection (when the host joins the network for 
the first time) or based on the identity of the host (as it moves 
around). I hope the model supports this somehow.

>  <owl:ObjectProperty rdf:ID="ie_poa_ip_addr">
Whose address is this, the access routers? Link local, global? Or the 
hosts? Again, can we have multiple?

Jari

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