Perhaps we can categorize external triggers to the PDP as follows (I am not claiming the list is exhaustive):
1. External triggers that are well-defined by the PDP implementation. For example, time of day, entering new policies, fault alarms etc.
2. External triggers that can come from the same PEP whose PIB will be affected. For example, COPS-RSVP messages or COPS-MIP (we have recently submitted this draft, it is still work-in-progress, but it lets the PDP track the user mobility etc). We can view this case as state-sharing among COPS clients. The PDP can identify the affected PIBs relatively easy, because PEPID is known.
3. External triggers coming from different PEPs, but their communication to PDP is defined. Examples are again COPS-RSVP and COPS-MIP etc. In cases where the PDP may want to pro-actively provision several devices as a result of signal coming from one device.
4. External triggers that are originated elsewhere, e.g. at some other servers, gateways etc. Their communication to PDP are unknown.
Yes, defining external triggers to the PDP are out of scope of the COPS protocol. Perhaps an informational draft that provides some guidelines on the possibilities of how these triggers could be handled, especially state-sharing among COPS clients could be very helpful to a COPS-PR implementer.
- Muhammad Jaseemuddin
-----Original Message-----
From: Durham, David [SMTP:david.durham@intel.com]
Sent: Tuesday, October 24, 2000 12:48 PM
To: Jaseemuddin, Muhammad [WDLN2:AN33:EXCH]; 'rap@ops.ietf.org'
Subject: RE: access request initialed by other sources than PEPs in COPS-P R
External triggers to the PDP are out of scope of the COPS protocol. It simply suggests they may be. I can give some other examples. Say a SIP message is received at the SIP gateway and is forwarded to a PDP. This PDP *implementation* may then have the smarts to send a provisioning DEC down to an edge router enabling QoS for the voice call (ie. marking the voice calls packets with the appropriate DSCP). This would require some basic topology knowledge at the PDP and appropriately configured role-combos at the edge router.
Another would be that an RSVP message is received at a RSVP&DiffServ capable device, is forwarded to the PDP, and causes the PDP to set the appropriate DiffServ policy on the same device for that RSVP session. This is an example of cross-talk between COPS-RSVP and COPS-PR-DiffServ as orchestrated by the PDP.
But again, this is a bit out of scope. There are endless examples of where external events from one device can affect configuration at another (or even the same device). Build or buy the PDP implementation that best suits your needs. The standards ensure that there is a way to communicate the events, and provision the appropriate policies.
-Dave
-----Original Message-----
From: Muhammad Jaseemuddin [mailto:jaseem@nortelnetworks.com]
Sent: Tuesday, October 24, 2000 7:49 AM
To: 'Rawlins, Diana'; 'Weilin Zeng'; 'rap@ops.ietf.org'
Subject: RE: access request initialed by other sources than PEPs in COPS-P R
For time of day its ok, because policy rules may have temporal conditions attached to them. But, for other external triggers, how would the triggers identify the PEPID and the PIB that will be affected? It is not very clear from the PR draft at least.
- Muhammad Jaseemuddin
-----Original Message-----
From: Rawlins, Diana [SMTP:Diana.Rawlins@wcom.com]
Sent: Tuesday, October 24, 2000 9:49 AM
To: 'Weilin Zeng'; rap@ops.ietf.org
Subject: RE: access request initialed by other sources than PEPs in COPS-P R
Weilin,
Yes, the PDP can detect external events and decide what policy decisions need to be made for what PEP. A simple example is Time of Day. The policy for filter markers may change at 6PM. The PDP implementation has rules to determine which PEP's are affected by the Time of Day event and changes policy accordingly.
-Diana
-----Original Message-----
From: Weilin Zeng [ <mailto:wzeng@ics.uci.edu>]
Sent: Monday, October 23, 2000 9:41 PM
To: rap@ops.ietf.org
Subject: access request initialted by other sources than PEPs in COPS-PR
Hi,
I encountered a problem when reading the COPS-PR. In Section 6(p27), the doc state that there is a case that access requests to the policy server can be initiated by other sources besides the PEPs. I think if the PEP don't initialize the request, the PDP cannot identify the PEP and cannot send the policy decision to PEP. Can anyone give me an explanation? Can this case be handled by COPS?
Thanks
Weilin