Loops (RE: CPIM changes)

--On torsdag, oktober 31, 2002 03:24:50 -0500 "Peterson, Jon" 
<[email protected]> wrote:

>
> Following Mr. Crocker's advice, then - is there anyone out there who
> cannot live without loop detection in impp-im-00?

I don't want to bias the group either way, but I've got an issue with the 
message below...

>> From: Dave Crocker [mailto:[email protected]]
>> Sent: Wednesday, October 30, 2002 10:04 AM
>> To: Peterson, Jon
>> Cc: '[email protected]'
>> Subject: Re: CPIM changes
.....
>> So we should ask the question: Can basic IM or Pres work without a loop
>> suppression mechanism defined in the standard.
>>
>> The answer is yes.  Email has worked without a standardized mechanism for
> 30
>> years.

I believe Dave's statement to be false.
Email has worked with Received: header counting for 30 years; we've even 
gatewayed them into X.400 and back out in order to preserve the loop 
detection property.

And yes, I've been on the sharp end of the stick in untangling loops caused 
by systems that wantonly threw away Received: lines. So has Dave.

Technical note: Any transport that can carry an arbitrary piece of 
"envelope" information between a gateway and the next gateway without 
munging it is capable of supporting a hopcount.

                         Harald





  [reminder: [email protected] for non-technical discussions, please]