re: Juniper Mum on Core Router...The numbers for the M160 are like this: - 160 Gbps for the fabric (bidirectional?) - 10 Gbps per slot - 8 slots So: - 80 Gbps of actual interface capacity
For the M320: - 320 Gbps for the fabric - 8 slots So... Does Gibson only support 20 Gig or interface traffic per slot? If Gibson support 40-Gig slots, i.e. each slot has 4 times the capacity of an M160 slot, then why is it called the M320? Did they make the box only capable of operating at half line-rate, or did they do the math differently? Should it really be called the M640, is it really only twice the capacity of an M160, or do the old boxes do "fuzzy math"?
re: Juniper Mum on Core Router...Yes but the M160 is half a rack too. How come the M320 supports 4x the slot capacity if it only has 2x the switch fabric?
- The packet processor on M40 can handle 8 OC48 ports, or 20Gb/s of full-duplex traffic - M160 uses 4 of these processors in parallel to handle 8 OC192 ports, or 80Gb/s of full-duplex traffic. It is still 20Gb/s per packet processor though. - Both M40 and M160 use a centralized packet forwarding architecture.
Based on this, my best guess is that for M320, Juniper changed from a centralized architecture to a distributed architecture. All they have to do is use one of the M40/M160 packet processors on each line card and connect these line cards with a centralized switch fabric. They could easily build a 8x20G or 16x20G system like this using most of their existing forwarding chips and some new queuing and switch fabric chips.
re: Juniper Mum on Core Router...Changing architectures is never simple. It isn't about what hardware can be re-used, it's about the software. If the software was architected for a centralized system it doesn't magically work in a distributed system. Much of the code, much of JUNOS, has to be re-written to support a new architecture. Whatever the M320 turns out to be, odds are high that Juniper will have to make trade-offs in schedule versus a new architecture. My bet would be they go for a better schedule and do what they can with exiting JUNOS.
re: Juniper Mum on Core Router...These newer players are taking a different approach to the problem. Unlike Juniper, which uses a centralized switch fabric in each device to process packets, these newer players have designed distributed routing systems. -------------
I would say that "some" of the newer players are doing architectures like this, but certainly not all. You sound like you have been talking to Pluris a whole lot.
------------ This means that some of the switch fabric in each device is resident on the line cards, and some is centralized as a means of interconnecting the cards. Software, too, is distributed, so the failure of one process does not take down the whole system but can be rebooted separately. This supposedly creates a "fault-tolerant" design, which is what many carriers say they want. ---------------------- This is wrong. The failures where one process takes down another are not really solved in a distributed system. All a distributed system will protect against (without further work) is failure of hardware components where the software is running.
re: Juniper Mum on Core Router... The numbers for the M160 are like this: - 160 Gbps for the fabric (bidirectional?) - 10 Gbps per slot - 8 slots So: - 80 Gbps of actual interface capacity
According to the spec sheet its full duplex throughput on the M160 per PIC. As you said 10 GBPs (duplex) per slot. I would agree that that is only 80Gbs of unidirectional capacity.
According to myresearch, the slot capacity has increased four fold (4 x 10) per slot. If the slot capacity has increased 4 fold, then yeah, sounds like it should be called an M640 to be consistent.
re: Juniper Mum on Core Router...I agree with the poster who surmised that the Internet Processor II ASIC ism oved to the line cards. That makes sense since the IP-II was capable of forwarding at 40G and if they are really building a 40G card that fits in well. I also read reports that the first line card that they will support is the 1-port OC-192 card which means that when the product comes out it will support only 8 OC-192 ports like the M160. Really confused!!
In any case, I will start believing when they deliver. Remember, even Tony Li did not think that the ASIC engineers at Juniper were competent. How are they going to pack 32 10G in a half a bay?
re: Juniper Mum on Core Router...I agree with the poster who surmised that the Internet Processor II ASIC ism oved to the line cards. That makes sense since the IP-II was capable of forwarding at 40G and if they are really building a 40G card that fits in well. I also read reports that the first line card that they will support is the 1-port OC-192 card which means that when the product comes out it will support only 8 OC-192 ports like the M160. Really confused!!
Perhaps they are only supporting 1xOC192 because there is no market for anything else?
I expect that Gibson is so slow in coming because Juniper has moved resources off it and onto projects that are going to make the company money. You know all those "edge PICS" that were announced right after this article, those are the things that are making Juniper money.
re: Juniper Mum on Core Router...Most of the discussion has been around whether Gibson CAN support 1x40G. Personally I think the more interesting question is WHEN should it support 1 x 40G.
40G slot capability is generally a good thing because it should let you deploy multiport interfaces (192c, 48c, etc) at a lower cost per port.
However, a single 40G port is a different beastie all together and brings a lot of questions such as:
Is there a pipe that really needs it? Is there transport infratructure in the ground/pipe capable of supporting it between two sites? Are there optics and framers available? Is anyone willing to pay the certainly high price in this market?
- 160 Gbps for the fabric (bidirectional?)
- 10 Gbps per slot
- 8 slots
So:
- 80 Gbps of actual interface capacity
For the M320:
- 320 Gbps for the fabric
- 8 slots
So...
Does Gibson only support 20 Gig or interface traffic per slot?
If Gibson support 40-Gig slots, i.e. each slot has 4 times the capacity of an M160 slot, then why is it called the M320?
Did they make the box only capable of operating at half line-rate, or did they do the math differently?
Should it really be called the M640, is it really only twice the capacity of an M160, or do the old boxes do "fuzzy math"?