The Pipe International blog is excellent, I followed it from start to finish while it was happening. It gives a real insight that has probably never been given before about the construction of a submarine cable, and some of the operational aspects (at least not on a free for all public blog).
Dont forget to read the comments section of each article, as additional questions and answers can be found there! Tom On 12 December 2011 03:02, Mark Tinka <[email protected]> wrote: > On Monday, December 12, 2011 06:54:14 AM Martin T wrote: > > > This isn't directly related with Juniper, but hopefully > > not totally off-topic as well :) At least here might be > > some industry insiders, who have some experience with > > submarine cables. > > It's operational in a way that affects the Internet, so I'm > happy :-). > > > 1) According to engineer in this video: > > http://vimeo.com/29975179 ..modern submarine cables are > > often built as self-healing rings. For example "FLAG > > Atlantic (FA-1)" between USA and Europe seen here: > > http://www.cablemap.info/ is a good example. How does > > such self-healing ring works? > > In essence, it's not that different from SDH or SONET rings > built on land. > > See here: > > http://en.wikipedia.org/wiki/EAC-C2C > > > However, it is also feasible that some cable operators > consider options for building 2x or more linear paths, as > opposed to ring topologies (ring topologies do have their > own sets of challenges, e.g., choosing the best route, > guarantees on latency, management, e.t.c.; which is not to > say that linear topologies do not bring with them their own > unique set of constraints - it's a balancing act). > > > Am I correct, that in case > > both cables are healthy, only one of two is utilized > > with traffic? > > Cable operators are unlike IP operators. They don't normally > load balance traffic across all available physical media. > > They could use the other part of the cable as a "Protect" > circuit, i.e., if you buy a service from the cable operator > and request for protection, the protection will be enabled > on the other part of the ring. > > Some operators run as many as 3x rings and designate that as > "primary", "secondary" and "tertiary". > > > Who provides equipment for such setups(I > > guess Alcate-Lucent is one of the vendors)? > > Key submarine equipment (SLTE) vendors are: > > o ALU. > o Fujistu. > o NEC > o Tyco. > > > Some of the terrestrial players are now looking to enter > this space, e.g., Huawei, Infinera, Nortel, e.t.c. > > > In addition, > > how long it will take such switch-over to occur? Are we > > talking about couple of milliseconds or few seconds? > > Cable operators offer 50ms failover for pre-provisioned > protect circuits. Typical electrical hand-offs to customers > are SDH or SONET, although Ethernet is now commonplace. I've > dealt with SDH and Ethernet only. > > However, I know some cable operators are considering > GMPLS/ASON which does provide protection, but may not be as > quick as 50ms. GMPLS, for example, uses an IP control > comprising: > > o OSPF-TE or ISIS-TE for routing. > o RSVP-TE or CR-LDP for signaling. > o LMP for link management. > > Of course, what we normally do is rather than buy a service > + protect circuit from the same cable operator, we buy 2x > service circuits from different operators so we can: > > a) Have both circuits active at the same time. > b) Reduce risk by using different providers. > > > 2) In case cable has multipoint landings(for example > > "GLO1", which has 15 landings in west coast of Africa > > and Europe) then submarine branching units should be in > > use. How this branching works? Are some waves(CWDM) > > inside the cables switched towards the landing and other > > continue via submarine cable? Because as I understand, > > on a wave level, we are still talking about point to > > point connections(?). In addition, are those branching > > units under the water or are they on small islands, oil > > platforms etc if possible? > > That is what is called an OADM-BU. You may take a look here: > > http://www.nec.co.jp/techrep/en/journal/g10/n01/100104-71.html > > http://blog.pipeinternational.com/index.php?option=com_myblog&show=The- > OADM-BU.html&Itemid=53 > > Hope this helps. > > Cheers, > > Mark. > > _______________________________________________ > juniper-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/juniper-nsp > _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
