Subject: issue comes from colip-BoF (flow mapping/aggregation)

From: [email-masked] (Hiroshi Esaki)
Date: Sun, 9 Apr 1995 15:38:33 -0400

Hi all, 

The following is the discussion related to packet flow mapping 
over connection oriented data-link platform. 

** When this issue is just a noise for you, please ignore this 
** mail and please let me say sorry to you. 

  (2) Packet flow mapping with data-link pipe and pacet flows 
      aggregation into data-link pipe.   Also, how to provide 
      a dynamic QoS requirement and T-spec changing during a 
      session over the connection oriented data-link platform
      (QoS negotiatin is besically connection-by-connection). 
          --> related with int-serv and ipoveratm. 

There seems to be two issues associated with this item. 

(i) How to mapp/aggregate the packet flows with/into connection 
    oriented data-link pipes.

    I think the use of data-link connections to transport the 
    IP packet flows is depend on router's local decision. 
    Some router will use a dedicated data-link pipe (e.g. 
    ATM's virtual connection) for each IP packet flow. 
    But, some router will use a dedicated data-link pipe for 
    IP packet flows whose requireing QoS class is the same, 
    i.e. packet flow aggregation. 
    First, I think, the mapping/aggregation method should be 
    clarified, with the clarification of benefits and drawbacks
    for each method.   The selection of flow mapping/aggregation 
    method will be decided by some factors (e.g. data-link pipe's 
    cost).    Typical example would be the packet flow transmission 
    over the WAN. 
       For the one-to-one mapping (i.e. IP packet flow is mapped 
    to a dedicated data-link pipe), over ATM, the parameter 
    mapping between T-spec/R-spec and Traffic-descriptor/QOS-parameter
    must be specified. 
       For the IP packet flow aggregation, the following factors 
    seems to be considered how to aggregate flows. 

       (a) QoS class (guaranteed, predictive, controlled-delay, best-effort)
       (b) destination
       (c) communication cost
       (e) security level 

(ii) How to dynamically change the QOS requirement (R-spec) and 
     flow description (T-spec) during a session over connection 
     oriented data-link platform. 

     By my understanding, the current connectin oriented data-link 
     platform providing the different level of QOS (i.e. ATM) 
     can not re-negotiate the QOS level during a session. 
     QOS negotiatin is session-by-session, in ATM.
     However, the model discussed in int-serv-WG must be able to 
     change the QOS class dynamically during a session. 

     Since, connection oriented data-link platform seems not to have 
     QOS re-negotiation capability during a session, it seems to be 
     worth to clarify how to provide dynamic QOS changing during 
     a session over the connection oriented data-link platform. 
     This seems, for me, to be quiet easy to from the view point of 
     router, i.e. just change which data-link pipe is picked up 
     for the IP packet flow.  

Best Regards, 

Hiroshi Esaki 
c/o CTR, Columbia Univ.