Comments on: Is OTN really the way forward? http://mccanntelecom.com/is-otn-really-the-way-forward European Telecommunications Markets and Events....from the trenches Thu, 10 May 2012 14:40:36 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Fred Stringer http://mccanntelecom.com/is-otn-really-the-way-forward/comment-page-1#comment-12 Fred Stringer Tue, 17 Nov 2009 15:45:12 +0000 http://demo.mccanntelecom.com/?p=4#comment-12 John, OK now I get your point. And yes I encountered the same thinking when we produced the xGE DWDM interfaces. The target application was metro/regional networks where passive DWDM systems were typically in place. There was always customers in the market asking for OTN framing in these interfaces. In my opinion there was two reasons for those requests: a) OTN was successful in the long distance optical networks therefore it most be useful here too, and b)perception that Ethernet alone can NOT be maintained with effective troubleshooting. I'm afraid we are not past the maintenance of Ethernet perception problem. Awhile ago when EFM (802.3ah) and CFM (802.1ag) were being deployed I searched for tutorials on Ethernet OAM and the enhancements these features provided. I did not find much, reinforcing the perception that Ethernet has little OAM capability, which I don't believe to be the case. Admittedly, the support mechanisms are different than SDH/SONET. I can't tell you how many times I've heard of point to point xGE WAN Phy deployments only because there it has OAM terminology and features familiar to the operations staff. Living with Ethernet still has many perception hurdles especially in the carrier market space. cheers Fred John,
OK now I get your point. And yes I encountered the same thinking when we produced the xGE DWDM interfaces. The target application was metro/regional networks where passive DWDM systems were typically in place. There was always customers in the market asking for OTN framing in these interfaces. In my opinion there was two reasons for those requests:
a) OTN was successful in the long distance optical networks therefore it most be useful here too, and
b)perception that Ethernet alone can NOT be maintained with effective troubleshooting.

I'm afraid we are not past the maintenance of Ethernet perception problem. Awhile ago when EFM (802.3ah) and CFM (802.1ag) were being deployed I searched for tutorials on Ethernet OAM and the enhancements these features provided. I did not find much, reinforcing the perception that Ethernet has little OAM capability, which I don't believe to be the case. Admittedly, the support mechanisms are different than SDH/SONET.

I can't tell you how many times I've heard of point to point xGE WAN Phy deployments only because there it has OAM terminology and features familiar to the operations staff.

Living with Ethernet still has many perception hurdles especially in the carrier market space.

cheers
Fred

]]> By: mccannte http://mccanntelecom.com/is-otn-really-the-way-forward/comment-page-1#comment-11 mccannte Sat, 14 Nov 2009 00:15:55 +0000 http://demo.mccanntelecom.com/?p=4#comment-11 Fred, from a FEC perspective you're absolutely right, increasing reach is obviously very useful. I also do see the advantages of OTN from a multiservice grooming perspective in the long haul. My main point here (obviously not made clearly ;-)) was to counter a number of Vendors claims that Metro/Access gear must evolve to be OTN compliant and to push OTN as a service delivery technology. I just do not see the point of OTN in an IP/Ethernet based service network. Now that I take a look at the post again, I didn't do a good job of qualifying my statement. Fred, from a FEC perspective you're absolutely right, increasing reach is obviously very useful. I also do see the advantages of OTN from a multiservice grooming perspective in the long haul.

My main point here (obviously not made clearly ;-) ) was to counter a number of Vendors claims that Metro/Access gear must evolve to be OTN compliant and to push OTN as a service delivery technology. I just do not see the point of OTN in an IP/Ethernet based service network.

Now that I take a look at the post again, I didn't do a good job of qualifying my statement.

]]> By: mccannte http://mccanntelecom.com/is-otn-really-the-way-forward/comment-page-1#comment-10 mccannte Sat, 14 Nov 2009 00:06:22 +0000 http://demo.mccanntelecom.com/?p=4#comment-10 Fred, you're right....I'm an IP guy and therefore usually overlook the advantages of a FEC. The main point behind the post (and perhaps not clearly stated) was to question the opinion that OTN has a place in the Access/Service portions of a Carrier's network. I just do not see any advantage of OTN technology in service delivery and I'm seeing a number of Vendors push this (and therefore some Carriers are starting to insist that their Metro boxes be OTN compliant). From a grooming perspective OTN has clear advantages in mixed use networks (OC-whatever + Fiber Channel + Ethernet) on the long haul, but in the metro or even in the European Country Networks, I just don't see the need..... Fred, you're right….I'm an IP guy and therefore usually overlook the advantages of a FEC.

The main point behind the post (and perhaps not clearly stated) was to question the opinion that OTN has a place in the Access/Service portions of a Carrier's network. I just do not see any advantage of OTN technology in service delivery and I'm seeing a number of Vendors push this (and therefore some Carriers are starting to insist that their Metro boxes be OTN compliant).

From a grooming perspective OTN has clear advantages in mixed use networks (OC-whatever + Fiber Channel + Ethernet) on the long haul, but in the metro or even in the European Country Networks, I just don't see the need…..

]]> By: Fred Stringer http://mccanntelecom.com/is-otn-really-the-way-forward/comment-page-1#comment-9 Fred Stringer Fri, 13 Nov 2009 23:35:11 +0000 http://demo.mccanntelecom.com/?p=4#comment-9 John, I think it is important to point out that OTN technology is very widely deployed. It is in most OEO Optical Transponders which are an element of long distance DWDM systems. What is new to the market is moving that technology to interface modules of routers and switches and providing Optical Network Elements like ROADMs a colored wavelength. One of the big advantages to OTN framing is the FEC (Forwarding Error Correction). The error correction solves with code some very hard physics problems and yields several db of gain for reach and/or hops. I think the question of "OTN Interfaces" in routers and switches is a bit different from the question of the OTN standards and technology. There is continual effort on various enhanced FECs with several deployed today. Given that "green field" implementations where you get to start with all new fiber are rather rare I'd expect the OTN technology to be deployed and enhanced significantly for many years. A good question is, where will it be deployed? I think the answer varies with distance and the topology of the optical network. It is not clear to me that the Ethernet evolution obviates OTN technology. John,
I think it is important to point out that OTN technology is very widely deployed. It is in most OEO Optical Transponders which are an element of long distance DWDM systems. What is new to the market is moving that technology to interface modules of routers and switches and providing Optical Network Elements like ROADMs a colored wavelength.
One of the big advantages to OTN framing is the FEC (Forwarding Error Correction). The error correction solves with code some very hard physics problems and yields several db of gain for reach and/or hops.
I think the question of "OTN Interfaces" in routers and switches is a bit different from the question of the OTN standards and technology. There is continual effort on various enhanced FECs with several deployed today. Given that "green field" implementations where you get to start with all new fiber are rather rare I'd expect the OTN technology to be deployed and enhanced significantly for many years.
A good question is, where will it be deployed? I think the answer varies with distance and the topology of the optical network. It is not clear to me that the Ethernet evolution obviates OTN technology.

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