In my thought, Ronny¡¯s idea is a
very useful one.
As pointed out from E. Yigal,
the proposed scheme of assigning a apecific multicast/broadcast connection CID
for L3 signaling broadcast traffic need some special treatment.
But, it is very useful and
necessary for IPv6 application.
If we should support IPv6, then
the IP address auto-configuration function requires a periodic broadcast of IPv6
Advertisement messages for IPv6 address allocation (such as ICMPv6 Router
Advertisement and/or Neighbor Advertisement), it is not appropriate for unicast
transmission. IPv4 Mobile IP is a different matter, so I am not going to say
about that. (It can be transferred to the unicast connection, and even 3GPP
people can take that approach.)
E. Yigal and DJ said that it is
possible and enough by assigning a multicast connection for the L3 broadcast
traffic. But it is not an efficient way. Because, if we use the multicast
transport connection for the L3 signaling broadcast, then the DSA procedure to
assign the MSS to join the multicast connection shall be carried out before the
L3 signaling broadcast. It gives more delay to the network entry than Ronny¡¯s
concept for using the pre-define transport connection CID for L3 signaling
broadcast. And it is problematic for the handover situation.
Ronny¡¯s approach is a good way
to transparently support the L3 signaling. E. Yigals approach requires that the
joining process of the multicast connection for L3 signaling broadcast assumed
that the BS MAC layer already know the necessity of that multicast connection (L2
involvement of L3 signaling, for example, by detecting the IPv6 support
capability). But, following the Ronny¡¯s scheme the L3 signaling broadcast is
periodically broadcasted and the every MSS¡¯s Layer 3 can detect that the IPv6 Advertisement
messages for IP Address Allocation not by involvement of the Layer 2 (MAC). So
it is a transparent way of support the L3 (or higher) layer signaling.
So, I think it will be the enhancement
of the current specification for future support to define the special transport
CIDs for L3 (or higher) layer signaling broadcast.
But, not forcing to use it. Systems
supporting the IPv6 will use it.
Best Regards,
Chulsik Yoon,
Senior Engineer, ETRI
From: Eliaspur, Yigal
[mailto:yigal.eliaspur@intel.com]
Sent: Friday, October 29, 2004 5:36 PM
To: Ronny (Yong-Ho) Kim; yigall@runcom.co.il; Al Dabagh, Baraa; ???; Iyer,
Prakash; STDS-802-16@listserv.ieee.org
Subject: RE: [STDS-802-16] Issues
for the usage of the Secondary management connection
Ronny,
Supporting
broadcasting over the data IP interface is possible by assigning specific
multicast connection CID for broadcast traffic (see 6.3.13 Establishment of multicast connections procedure)
This
mechanism allows you:
- To specify specific parameters to the
broadcast connection: e.g. CS type, QoS parameters, SAID etc.
- To define more then one broadcast ¡°virtual
groups¡±
- To utilized the broadcast concept in dot 16
layer.
Defining
a new constant management CID value for broadcasting requires special
treatments for bullet no. 1 above and has no support for bullet no. 2 above.
Regards,
-
Yigal
-----Original
Message-----
From: Ronny (Yong-Ho) Kim
[mailto:ronnykim@lge.com]
Sent: Thursday, October 28, 2004 6:48 AM
To: yigall@runcom.co.il;
Al Dabagh, Baraa; Eliaspur, Yigal; '???'; Iyer, Prakash;
STDS-802-16@listserv.ieee.org
Subject: RE: [STDS-802-16] Issues
for the usage of the Secondary management connection
Dear
All
We
are discussing managing IP interfaces either for Data or for Management in
mobile environment.
For
IP interfaces, somehow Layer 3 signaling from the network should be transferred
to the MSS in order to manage connection and we have discussed how it can be
conveyed. We haven¡¯t quite agreed which way is the best way.
Here,
I would like to raise little different issue. If an MSS decides to use Mobile
IP or IPv6 for Data or Management, not only unicast layer 3 control signal but
also broadcast control signal from the network should be delivered to the MSS
for IP interface management. However there is only unicast way to deliver this
layer 3 broadcast signal through 802.16 air interface. If the layer 3 broadcast
signal is transferred through default connection or secondary management
connection, it will be a waste of resources. Someone might say it is not
necessary for a BS to deliver layer 3 broadcast control signal to MSSs, however
if the broadcast messages are not delivered, each and every MSSs, which are
supposed to receive broadcast layer 3 control messages periodically, will
generate unicast layer 3 signal, e.g, Agent Solicitation, or Router
Solicitation through default or secondary management connection and unicast
reply from the router or Agent to MSSs will be generated. This is even worse
waste of bandwidth.
If we define
a new management CID to deliver broadcast layer 3 management signal to the
specific MSSs in a multicast way, then we can make IP interface management more
efficiently. This management CID is only for certain MSSs that use MIP or IPv6.
I would
like to hear your opinion on this.
Thanks,
Ronny
From: owner-stds-802-16@listserv.ieee.org
[mailto:owner-stds-802-16@listserv.ieee.org]
Sent: Monday, October 18, 2004 5:52 PM
To: STDS-802-16@listserv.ieee.org
Subject: Re: [STDS-802-16] Issues
for the usage of the Secondary management connection
Dear Chulsik, Ronny, All,
I would like to summarize the different options
raised in this email thread with regards to Management Connection.
Please let me know your preferred option (of the
below) so we can all know the baseline that each one of us starts from. Also
let me know if I missed some options.
1.
MSS uses
only one IP interface (both for data and management). Layer 3 and above
protocols of this interface are used also for MSS manageability.
Implementation options:
1.1. MSS chooses ¡°un-managed¡± SS
capability mode, open default data connection using static DSA (with much all
classifier) to carry all default data traffic (including MIP/DHCP, TFTP, SNMP).
2.
MSS uses two
IP interfaces, one for Data and one for Management. MSS has duplicated layer 3
services (for each interface).
Implementation options:
2.1 MSS chooses ¡°managed¡± SS
capability mode, use the secondary CID to carry DHCP,TFTP,SNMP of the
management IP interface. Open a default data connection using static DSA (with
much all classifier) to carry all default data traffic of the data IP interface
(including MIP/DHCP, TFTP, SNMP).
2.2 MSS chooses ¡°managed¡± SS capability mode, use
the secondary CID to carry DHCP,TFTP,SNMP of the management IP interface and
MIP/DHCP,TFTP,SNMP of the data IP interface. Open a default data connection
using static DSA (with much all classifier) to carry all default data traffic
of the data IP interface (excluding MIP/DHCP, TFTP, SNMP).
2.3 Same as 2.1 but with MIP
capability on the Management connection IP IF.
2.4 Same as 2.2 but with MIP
capability on the Management connection IP IF.
Currently the standard supports only option 1.1
and 2.1 above.
The disadvantages I see for 2.2. 2.3 and 2,4
above are as follows:
2.2 – If both IF shared the secondary CID, then
how can the Network/BS conclude which of the IP allocation requests (MIP/DHCP)
is for the data IF and which is for management IF. As for my understanding this
was the aim of the Secondary CID connection.
2.3 – This solution can be applicable, however
it requires the BS/Network to allocate two sets of colocated/home IP addresses
and to maintain two mobile IP sessions in parallel, one for the Management
connection and one for the Data one. IMO, it raises unnecessary complexity and
usage of system expensive resources. In addition it can have high impact on the
HO performance requiring to maintain two separate MIP HO procedures.
2.4 – Sheared disadvantages of 2.2 and 2.3.
Notes:
1.
¡°un-managed¡±
mode explicitly define the lack of secondary CID.
2.
DSX
transaction can create default CID between the BS and the MSS without a need
for neither IP/Layer3 information nor connectivity.
BR,
- Yigal
Yigal
Eliaspur
Intel
Corp.
yigal.eliaspur@intel.com
-----Original
Message-----
From: Ronny (Yong-Ho) Kim
[mailto:ronnykim@lge.com]
Sent: Sunday, October 17, 2004 9:32 AM
To: Eliaspur, Yigal;
STDS-802-16@listserv.ieee.org
Subject: RE: [STDS-802-16] Issues
for the usage of the Secondary management connection
Dear Yigal and
Chulsik,
Basically, I agree
with Chulsik on the SMC issue.
I have comment and
question on Yigal¡¯s opinion, please refer to my
comments inline.
B.R,
Ronny
LG Electronics,
Inc.
From: owner-stds-802-16@listserv.ieee.org
[mailto:owner-stds-802-16@listserv.ieee.org]
Sent: Saturday, October 16, 2004 6:00 PM
To: STDS-802-16@listserv.ieee.org
Subject: Re: [STDS-802-16] Issues
for the usage of the Secondary management connection
Hello Chulsik Yoon
Please find my comments inline...
Best regards
- Yigal
Yigal
Eliaspur
Intel
Corp.
yigal.eliaspur@intel.com
-----Original
Message-----
From: csyoon@etri.re.kr
[mailto:csyoon@etri.re.kr]
Sent: Friday, October 15, 2004 4:09 AM
To: Eliaspur, Yigal
Cc: STDS-802-16@listserv.ieee.org
Subject: Issues for the usage of
the Secondary management connection
Hello Yigal,
I would like to discuss the usage of the
Secondary Management Connection.
In the current draft standard, the usage of
the secondary management connection is described like this (it is the result of
the last meeting in Seoul,
comment #580):
¡°Finally, the Secondary Management
Connection is used by the BS and MSS to transfer delay tolerant,
standards-based [Dynamic Host Configuration Protocol (DHCP), Trivial File
Transfer Protocol (TFTP), SNMP, etc.] management messages.¡±
-- The text having the meaning that Mobile
IP messages and router prefix advertisement are not transferred through the
secondary management connection.
We have talked about the issues in the
meeting, but we have found out some differences in our understanding, and the
problems in the current specification.
You said:
The Secondary Management Connection can be used only for the management
purposes, not for a user traffic transport, such as the SNMP messages for the
SS. The IP address allocated by using the DHCP is used only for the management
for the SS, not for the user traffic. The IP address for the user service can
be allocated using the ¡°default¡± Transport Connection. And the parameters for
default Transport Connection is pre-assigned in each Base Station (BS).
But, these ideas have some problems:
1) You mean that the protocol layer for the SS management (i.e., SNMP)
is within the layer 2 (MAC) of the SS, and the path to that is on the Secondary
Management Connection. And the user traffic (even in the case of DHCP or Mobile
IP message for the IP address allocation for the user traffic) cannot use the
secondary management connection.
In that case the protocol layers for the IP and above should be duplicated in
the user plane and the management plane. But, the SNMP for the SS management
and the Mobile IP for the IP connectivity management for user traffic can be
discriminated in the IP layer by the ¡°protocol¡± field. So, the two protocols
can be well harmonized using the secondary management connection. And, it is
not required to implement the duplicated protocol layers for the management
plane and the user plane. The SNMP and the Mobile IP can be distinguished as a
different application on the same IP layer. It is the better approach.
[E. Yigal] The current specification (16e/d)
provides management mechanism that was mostly inherited from DOCSIS
specification, and was design for fix SS (RG like) operation. This management
framework requires 2 separate IP IF, one for Data traffic and one for
Management traffic. The Management IP-IF is consider part of the 16 MAC and as
a result the standard includes explicit reference to its layer 3 and above
protocols (DHCP,IP,TFTP,SNMP). E.g : IP connectivity and TFTP stage in
the network entry, the definition of the Secondary Mgmt connection, etc.
An experiment to enhance the Mgmt IP-IF to
Mobile operation by replacing DHCP with MIP was a failure as for the amount of
complexity it brought.
The aim of 16g is to define applicable and scale
Mgmt solution for mobile operation, and this might be done using MAC layer Mgmt
singling (not IP/SNMP based).
[Ronny] My question here is what kind of problem
is caused if Secondary management connection is used for MIP? You mentioned
replacing DHCP with MIP causes a lot of complexity but I disagree. Acquiring
management IP address using MIP is very similar to DHCP if we consider MSS
solicits Agent Discovery. If HO with MIP causes problem, DHCP causes same
problem. However, as you know, MIP provides better IP management scheme than
DHCP for mobiles.
Of course 16g can provide scalable Mgmt solution
for mobile operation, but mobile management should be handled with IP address.
Therefore, we can just have simple solution by
using Secondary management connection for MIP and if there is any problem then
we can fix it in either 16e or 16g.
2) If we shall use the default transport connection for the IP
connectivity management for the user traffic, then the DSA procedure should be
proceeded before the allocation of the ¡°default transport CID¡± for the user.
But, generally DSA procedure requires the IP address for the transport
connection, and even if it is not required, the ¡°default transport connection¡±
allocation is not possible. If we use the transport connection for the transfer
of the Mobile IP and/or DHCP messages for the IP connectivity for the user
traffic, then the IP address related parameters for the DSA procedure cannot be
set. That means the parameters required should already be known to the SSs and
the BSs. The default parameters should be used.
Because, the procedure is not described in anywhere in the specification, the
BS cannot provide the allocated ¡°default transport CID¡± to the user. In what
management message? Using what parameter?
[E. Yigal] If the network/BS cannot allocate in
advance (before operational stage) a co-located IP address based on the SS MAC
address, the network/BS shell open a default data CID with a classifiers that
is agnostic to a specific IP address (e.g. much all classifier). Once it has
knowledge of the IP address and other higher level information (like ports) the
system, based on needs, can triggered dynamic DSx with the appropriate
information (note that more then one CPE IP address is possible in RG like
environments).
[Ronny] I can not see the case when the network/BS
can allocate a co-located IP address based on the SS MAC address. The function
of default data CID looks pretty much like Secondary management connection to
me. Why do we need to define a new default transport CID instead of SMC?
3) If we should use the (default) Transport CID for IP connectivity
management for the user traffic, then every terminal shall maintain the Basic
CID, Primary Management CID, Secondary Management CID, and default Transport
CID for signaling/control. That means SS should have minimum 4 CIDs , but the
specification say that the minimum required CIDs each SS should have shall be
not four but three. So, the usage of default Transport CID violates the specification.
[E. Yigal] This is a network/operator decision if
to provide the MSS data connectivity or not by allocating default data CID.
[Ronny] If default data CID is given to the MSS by
a network/operator then it is required for MSS to manage this connection.
4) If we use Transport CID instead of Secondary Management CID for the
IP connectivity management for the user traffic, then the additional
DSA-REQ/RSP procedures should be included in the network entry process. The DSA
(connection establishment) procedure must be preceded for the transaction of
the IP connectivity management procedures (DHCP or Mobile IP), because we
should use the connection established before the transaction. But, if we use
the Secondary management CID for that transaction, then the connection
establishment procedure is not required. That means, the usage of the (default)
Transport connection have more signaling overhead and causes more delay during
the network entry process.
[E. Yigal] As I specified above the default data
CID can be agnostic to the IP layer an above addressing, in addition static DSx
operation is part of the network entry process.
5) In the fixed environment, a subscriber station (SS) can be separated
with equipment for the user traffic (such as multiple TEs) and the equipment
for the air interface (such as MT), so that the Secondary management connection
for the IP-based external management for the SS is feasible. But, generally in
the mobile environment, the two equipment (TE and MT) should be integrated and
used by only one user, so the separation of the path for the user traffic IP
connectivity management (default transport CID) and for the external
management for the MSS (Secondary Management CID) is not a good approach.
Therefore, even in the case of the Secondary management connection is used for
the external management for the MSS, the Secondary management connection should
also be used as the transfer of the user traffic IP connectivity management and
management (Mobile IP or DHCP).
-- We need to define the concept of MSS clearly. I think that the Mobile Router
(One modem and multiple user equipment in mobile situation) concept is not
appropriate for the current 16e specification.
[E. Yigal] As I specified above the Secondary
Management connection is not applicable for Mobile
operation.
6) If we use the Secondary management connection only for the IP-based
management of the SS externally, then the IP address for the SS management and
the IP address for the user traffic (you mean, using the default transport
connection) should be different. But, the IP address for the user traffic and
the SS management can be shared, and has no problem. So, the separate IP
address allocation procedure is duplicated and cause wasting up the IP address
resources, especially in the case of MSS.
[E. Yigal] There are cons and pros for shearing
or splitting IP based Management addressing with the data addressing. The
standard does not prevent you to share the two addressing and to use the data
only address. You can do that by choosing the ¡°un-managed mode¡± capability –
which means it¡¯s out of the standard scope to deal with/define it.
7) If we use the transport connection for the user traffic IP connectivity
management, then the CID resources should be thrown away unnecessarily. If we
can reuse the Secondary management connection, then we can save the CID
resources.
8) If we should proceed the handover process in the mobile environment
over the subnets, then the transport connection for the user traffic IP
connectivity management should be preceded before the transfer of the Mobile IP
messages, that gives us a large unwanted delay for the handover process, and
the system performance shall be greatly degraded.
[E. Yigal]
Agree, see above – this is why we are looking for another solution for mobility
(e.g. MAC mgmt based) in 16g
In summary, I would like to say my
understanding and concept, and the specification should be reflected to support
that:
1) Secondary management connection can be used as a user traffic IP
connectivity management (DHCP or Mobile IP).
2) The IP address allocated by the DHCP procedure using the Secondary
management connection, can be shared for the user traffic and the external
management for the SS. So, there is no need to separate the path to the SS
management and the user traffic by secondary management connection and the
transport connection.
3) Mobile IP should be supported for the seamless HO across the
subnets, and for the swift handover process, the Secondary management
connection should also be used for the Mobile IP message transfer and the
external management for the MSS for the managed MSS.
Best Regards,
Chulsik Yoon
Senior Engineer, ETRI