Monday, June 30, 2008

PMC-Sierra White Paper on 10 GigE

PMC-Sierra has released a white paper on their 10 Gig reference design. While the paper does not talk about much technical details on 10 GigE, it does try to motivate 10 GigE the obvious way, IPTV. It talks about the growing demand for HDTV, and how people with multiple set top boxes would require bandwidth that can be provided by 10 GigE solutions. Nothing much new, but may be interesting read for those in this field. Paper may be downloaded from (Registration required).

Saturday, June 28, 2008

Welcome to our new readers

We are now using Google Adwords to advertise this blog, and we welcome new readers who are discovering our blog via this channel. A quick introduction to this blog, we have discussed developments in Ethernet and related technologies for close to three years now. Feel free to contribute to current posts.

We have also an excellent search feature now, again courtesy google. We regularly refine and update this, and we recommend you to use this to find other posts and lively discussions on this blog.

Happy reading.

Thursday, June 26, 2008

Comcast reports testing 100 GigE

Comcast today issued a press release stating that it had successfully tested 100 GigE over its backbone network between Philadelphia and McLean, VA using Cisco's 100 GigE interface for its CRS-1 platform. The release also mentions that Comcast followed the specifications for the IEEE 802.3ba standard for 100 Gig Ethernet.

While this makes Comcast one of the first service providers to test a 100 Gbps point-to-point tunnel, I would like to remind my readers that this itself is not a major technological achievement, however colorful the news may read. Dense Wavelength Division Multiplexing (DWDM) has existed in backbone networks and the optical world for several years now. So has the Cisco CRS-1 which can route multiple OC-192 (equivalent of 10 Gbps in the optical world) and OC-768 (40 Gbps). In fact Cisco claims that its CRS-1 can route upto 92 Terabits of traffic. I was not aware of a 100 Gbps interface to the CRS-1 before, but I presume that Cisco has it now, at least in prototype.

So carrying 10 optical channels across a backbone network is not something new. What's new about this I presume is that the 10 optical channels are delivered over a single interface which follows the 100 GigE IEEE 802.3 ah standard. Moreover 100 GigE has to my knowledge not been demonstrated before on a WAN, although there are previous studies from Lucent and AT&T showing 100 GigE on a LAN. For those unaware, the IEEE 802.3ba draft deals with how to handle several 10 GigE channels on a Ethernet interface. I am curious about which vendor Comcast worked with for the 100 GigE end interface. Opnext and Hitachi are the two companies having EA-DFB Lasers that can support 100 GigE according to this article.

Monday, June 16, 2008

EPON supporting DOCSIS from Salira

Apologies to my readers for no updates over the last month-and-a-half, I was busy traveling. There have not been any major updates in our field, except for the news of Salira releasing DOCSIS support for its EPONs.

The idea is to use EPONs as a feeder network for Cable TV networks. DOCSIS 3.0 which has been standardized recently and is still under trial deployment by Comcast and others and support downstream bandwidth is excess of 12 Mbps. PONS seem the natural choice to act as feeder networks.

However, this idea is not new. CATV networks already use fiber as a feeder till the last mile where copper takes over. EPONs have also been suggested earlier as feeder networks to VDSL, whose reach is much shorter. So much is to be seen on how Salira plans to market this.