Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: [EFM] RE: Pause frame usage in transport networks




Roy,

I disagree with the statement 
	"If they deployed technology based on G.gfp, they can't 
	generate pause frames to provide rate limiting..."

While "G.gfp"  (G.7041) does not explicitly address generation, termination,
or transport of pause frames (or other Ethernet/MAC-specific control
functions), this does not mean that equipment that uses GFP is prohibited
from dealing with pause frames (or any other Ethernet/MAC-related functions
that are beyond the scope of G.7041).
G.7041 does not have, does not need, and should not have, "support for"
802.3x pause frames - 802.3x does.
I am aware of equipment that both uses G.7041 and provides options for
transparently transporting and for terminating/generating pause frames to
satisfy various applications.

Jeff Towne

	-----Original Message-----
	From: Roy Bynum [mailto:rabynum@mindspring.com]
	Sent: Friday, February 21, 2003 2:37 PM
	To: Shahram Davari; 'Siamack Ayandeh'
	Cc: Ben Brown; Geoff Thompson; mattsquire@acm.org; Chau Chak;
	stds-802-3-efm@ieee.org
	Subject: RE: [EFM] RE: Pause frame usage in transport networks

	Shahram,

	Depending on the technology that the major carrier you refer to
implemented 
	in their initial deployment, it may be more of a case of they
"can't" 
	support active flow control instead of they "don't".  If they
deployed 
	technology based on G.gfp, they can't generate pause frames to
provide rate 
	limiting and are thus the customer is totally dependant on his own
internal 
	bandwidth management, which can be very expensive.

	The last time that I looked at it, G.gfp does not have support for
802.3x 
	pause frames.  The initial transmission vendor offerings based on
G.gfp do 
	not have the capability to generate Ethernet "pause" frames.  Later 
	versions of G.gfp may include the use of 802.3x MAC control frames
and the 
	transmission equipment vendors may implement it.

	...