The debate still lingers on. When it comes to protection and re-routing on High speed links, what is the benefit of using Optical ASON versus Electrical ASON.
The Optical ASON relates to lambda switching ( Also called WSON-Wavelength Switched Optical Network). This necessitates the need of using at minimum Multi degree and directionless functionality. Using colorless functionality gives more degree of freedom and flexibility since in case of non-availability of a particular wavelength, ROADM has the functionality to change the color of wavelength also. When it comes to Electrical ASON, it is referred to as “ODU switching” at electrical layer of OTN switch. This necessitates the use of OTN switch along with ROADM. While Optical ASON gives one an advantage of lambda switching; the Eletcrial ASON gives advantage of control over more granular traffic at ODU level going as low as 1G traffic. In contrast, lambda switching can help to save on transponder resources because the same transponder can change direction or color thus there is no need to have multiple transponders for multiple restoration paths-a benefit not available on electrical ASON which would need multiple lambda paths to be created from Day one. Electrical ASON on the other hand gives much faster restoration times compared to Optical ASON. So what is the verdict ?
The rule of thumb is following: If traffic granularity is less and the lambda is not filled completely, Electrical ASON is much more optimized and cost efficient, on the other hand if lambda is filled with traffic ( multiple ODUs occupying complete lambda) that needs same SLA of restoration ( Meaning complete Lamda needs to be switched) then Opitcal ASON is much more optimized and cost efficient and ends up saving on the number of transponders.
Hello Faisal,
what about electrical ason for 100ge? is it better than optical ason for long hub for 100g lambda system? or same as optical ason requiring regenerator if optical parameters not optimal.
as multiple 10g to different direction are regenerator as each add\drop nodes.
br,
ashish
Hi Ashish,
100GE ASON will only make sense if the lambda is 400G or above. Currently I dont see any value if the lambda is 100G.
Thanks Faisal for your reply. Does optical ason can gurantee under 50ms protection with 1+1+r and 1+1 protection.
You will use ASON mainly for restoration and not protection. Any 1+1 protection will guarantee 50 ms. 1+1+r will guarantee 50 ms even for more than 1 fiber cut.
Dear Faisal:
we can use optical ASON for working + Protection if in case we use transponder level protection.
correct me if i am wrong
you can configure two transponders ( working and protection) seprately in optical ASON mode. So that means yes to your answer.
Hi there, after reading this amazing article
i am also delighted to share my familiarity here with mates.
Good Day
Please advise if Optical ASON is exactly the same as WSON as there is no clarity. Can you explain why you state that they are the same? thanks
Thanks Mary,
The right name should be WSON. As WSON is a standard but optical ASON is just an industry term. But the industry is using the word interchangeably. Yes they are same but a word of caution. Sometimes the vendor would use the word optical ASON to mean that they support optical control plane without satisfying the detailed framework of WSON. For example WSON would mean that the equipment can switch based on optical impairments also in addition to fiber cut. Some vendors dont support switching on optical impairments. therefore they prefer to use the word optical ASON instead of WSON as then they just support a subset feature of WSON but not full WSON.
What are the switching times for both the technologies?
In general the restoration in Optical ASON is slower, may be in minutes. In electrical ASON, I have seen close to 200 msec or more.
Hi Faisal, how many simultaneous circuits are tipically restored <200ms for OTN ASON?
Thanks Marcos, depends, as it is also dependent on how much bandwidth is available for restoration.
I am having 40 channel 100G OTN with 6 directions. Its having UXU2 (Cross connect card) which connects service cards to Transponder. This OTN also have WSS8 card. We r using 2 channels 39,40 in each direction. I want to know in case of fiber cut in 1 direction how will the WSS switch the traffic to other direction as we r using same 39 and 40 channel in each direstion.
Dear as you are using OTN, so in this case you dont need to use WSS switching. As OTN swithing is enough. You are using electrical ASON and not optical ASON
Thanks for ur prompt reply. I am new to OTN. We r using Fiberhome FONST 5000. I want to ask if we r using electrical ASON, then why did the pair of WSS8 and ODU8 used in the WDM shelves. The WSS is interconnected to all other 5 direction WDM’s WSS. Also, does the 4 UXU2 cards will be able to ASON the 40x100G data in case of fiber cuts?
Hello Abhay,
As far as the FONST 5000 concern it’s only support DWDM, and its upgrades version U20 is having OTN feature, now answer to your question, they are using a pair of WSS and ODU in every direction to make it fully functional ROADM configuration, also you must be using 1 or 2 pair for local add drop as well. So you can understand like that directions or path calculation can be done by WDM cards and switching and restoration is being carried out by UXU2.
Hi Vishal
We are using 2 Lambdas in each direction and all the lambdas terminates at U20 rack using 1LN4 transponder card.
Is this ROADM dynamically reconfigurable or manual configuration is required, if more lambdas were used and switched using WSS?
Dear ABHAY
I hope all is fine
could you please give me information about cross connection of U20/U60 product of Fiberhome ?
is restoration time differ according to ason level (diamond -gold -servrr…)
Hi, yes it is
Hi Faisal,
Thanks for your post..
Could you please explain importance or need of using GMPLS protocol? what does it do?What are the parameter concept based Both Lambda / ODU switching happening?
GMPLS is a generalized MPLS which can used anything as resoure for labeling. In case of DWDM , the resource is lambda, in case of OTN , it is ODU.
Hi Faisal,
I have a doubt in ROADM-Reconfigurable optical ADD/Drop Multiplexed.
I have a ROADM Mux ,its connected to 3 different direction lambda(different colour,A,B,C).Assumption: Each lambda capacity 10G.’A’ lambda carrying 10G full traffic, B & C lambda carrying 5G traffic compared to less traffic in A. Now A lambda carrying 10G got failure, So now ODU traffic will be switch over to rest of the B & C lambda(different colour).
In this scenario, Is protocol decide to switch the Shared traffic to different Colour Lamba? And also this switching will be happened automatically or manually?
Kindly advice.
ROADM may do optical GMPLS, therefore it will switch full 10G switch, rather than sub lambda switching
Dear Faisal
I hope all is fine
many thanks for amazing article
Could you please give me information about FONST5000 Fiberhome and implementation of wson and ason in this equipment
Thanks Mohammad, Really have no idea about this product
Dear Faisal
Many thanks for your attention
if possible please give me information about GMPLS and how the vendors used this protocol for switching
Thanks Faisal for an informative article. Can you please write an article on DWDM vs OTN (Optical and Electrical Sub layers and switching technologies use in both) and also Muxponder vs Transponder
Hi there,
Thanks for the post but I just had to mention that I found another copy of the same article with minor alternation at older date but from another author and it would be better if the copyright of the original author is maintained, you may check the below link:
https://support.huawei.com/huaweiconnect/carrier/en/thread-120775-1-1.html
Thanks Mostafa, My post was published way back in 2013, before the post appeared on Huawei support forum. I will have to reach out to Huawei to raise this issue. Thanks for bringing this up.
Faisal Bhai please explain what difference between ASON ,and OTN.
Hello Syed, thanks for commenting. There is no relation between them. ASON is a control plane while OTN is a transport technology