What are the limits on the number of nodes in an erp ring? Does the number of add/drop ports affect this number?
Hi Mark - thanks for your question. I am reaching out to the appropriate parties to get an answer, and hope to have one for you as soon as possible. In the meantime, feel free to reach out with other questions, or to share our thoughts on our new community. We will talk soon - thanks again!
We reached out to some Z-Series experts. The answer is that up to 16 nodes are officially supported, and this is based on the G.8032 standard. Hope this helps, Helen
Does the number of Add/Drops used on those nodes affect the number of nodes that can be supported on a ring?
No, the number of add/drops does not affect the number of nodes on the ring. Assuming 16 nodes, they can all be add drop and 50ms switch time should still be maintained.
This is a first post as a new community member and I am very grateful Ciena has create this forum.
I currently have 5 nodes in my G.8032 ring with the core switches being 5150's and 5160's because I needed the high port density. I currently have 110 nodes hanging off the add/drop core switches. The G.8032 ring is at 10Gbps. I have not had any issues as I increase the number of nodes off of the ring. At only 5 core nodes on the ring, I am getting less that 5ms switch time. I have even added a sub ring to two sides of the ring to protect customers on one of my long(close to 80km) distances between core ring switches. I do keep a spreadsheet of subscribed bandwidth so I am constantly aware of my current potential of bandwidth utilization on the ring so I don't over saturate my 10Gbps pipe(That is a limitation I do watch closely). Attached is a graphic from my current Ciena G.8032 ring.
The primary objectives of erp/8032 are loop prevention and protection switching. The 16 node limits that most suppliers adhere to are largely predicated on a maximum ring circumference. I believe ciena has locked in on 1000km. The two factors that affect switch times are 1. inflight time on the fiber 2. fabric processing time. It's very possible that you could exceed the 16 node limit provided you had a very small ring circumference. The number of circuits/services should not have an impact on the ring performance provided your control traffic is prioritized properly and doesn't have to compete for BW on the ring.
I hope this helps.
First time poster here...this is exactly a question that I have regarding G.8032 design. I have a main ring with 15 nodes on the ring (estimated ring circumference is 180km). I don't think there should be any issue as this falls within the standard.
My concern is with my sub ring which has 19 nodes and connects to two nodes on the main ring. The estimated circumference is 320km. All of the nodes are 3952/5160's and all links are 10Gbps.
Can you confirm that Ciena will support this design even though it exceeds the 16 nodes on the sub ring? Is there any supplemental documentation that is available to base my justification on the 1000km limitation?
Thanks in advance.
Hi Andrew, welcome to the community. To discuss your design, we think it would be best, and recommend, contacting your SE team/partner or our technical support team at 1-800-ciena24.
Thank you. I just spoke to an SE and he said that the Ciena guidance for G.8032 was to stay less than 24 nodes in a ring and under ring circumference 1000km. (to try and keep under 50ms recovery time) Good news for me.
Excellent, glad to hear!! Thank you for sharing an update with us too.
Have a great weekend.
There is no practical limit to the number of add/drop nodes you can have in an ERP, however the G.8032 standard calls out 16 nodes as the number for which sub-50ms switching is expected.
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