Dear all,
I am in process of planning ring network to cover 15 POPs in City. Some technologies are chosen for consideration like SDH(Huawei), PVRST+(Cisco), RSTP(Zyxel), EAPS (extreme network) and MPLS(VPLS). The purpose is to provide L2 Ethernet connectivities from POPs to central point (DC) and ring protection.
I know you all are in those network for years. can you give me some advises?
Best regards,
chanty
Step 1: Don't mix vendors. Period.
Only one vendor will be chosen.
Step 2: Hire a network consultant that gets paid for its job.
I'd strongly suggest trying to avoid a large, multi-geography layer-2 topology, and instead work to separate it out via layer-3. Otherwise, you're just asking for trouble, IMHO.
Of the above, VPLS.
But it really depends what you need to do. If you're selling customers cross-town L2 services then yeah VPLS is the best option in my opinion.
If this is for use between your own equipment, other technologies might make more sense.
I echo Roland's comment, but I'll make it more specific - stay away from anything with spanning tree in it.
There are several ring technologies that are interesting but again it depends on what services you are planning to run and what kind of SLA guarantees you need:
- RPR (802.17) : This has quieted down but it is a fairly robust technology giving you packet rings with 50ms, CoS, fairness and upto 255 nodes in a ring
- EAPS: This technology is more vendor specific (eventhough an informational RFC exists)
- ERPS (G.8032 - ITU) : This standard from ITU folks supports ethernet based packet rings and is comparable to EAPS
- SONET/SDH : This is tried and tested but do you want to deploy a TDM based technology if most of your traffic is packet based
- MPLS/VPLS : This is a layer 3 based and may not work for pure layer 2 service providers. It is tried and tested but does have some operational complexity built-in compared to layer 2 based technologies
I agree with an earlier suggestion made, do not mix vendors if you want service level interoperability.
Vinay Bannai
Email : bannai@pacbell.net
> I am in process of planning ring network to cover 15 POPs in City.
> Some technologies are chosen for consideration like SDH(Huawei),
> PVRST+(Cisco), RSTP(Zyxel), EAPS (extreme network) and MPLS(VPLS).
> The purpose is to provide L2 Ethernet connectivities from POPs to
> central point (DC) and ring protection.Of the above, VPLS.
Strongly disagree. VPLS gives you ample rope to hang yourself. An L2
ring-based protocol like EAPS is much simpler to deploy.
Steinar Haug, Nethelp consulting, sthaug@nethelp.no
Hi there,
Keep it really simple. MPLS/VPLS is the most scalable method to create Layer 2 and Layer 3 connectivity between sites. As previously mentioned, try to stick with one vendor, one code version for all the POPs, and use protocols that are designed to scale well. (ie. MP-BGP)
If your goal is to provide layer 2 around across all 15 POPs you don't actually need to build a ring. With MPLS/VPLS you can use any topology that provides you the necessary efficiency and reliability.
MPLS can be used on any of the transport technologies that are available to you (ie. SDH / dark fiber / dwdm / etc) ...
Kind regards,
Truman
My vote goes to proprietary ring protection from the vendor you choose:
- EAPS (Extreme)
- REP (Cisco)
- MRP (Foundry/Brocade)
- EPSR (Allied Telesis)
Although EAPS is implemented in all Extreme switches, select models
from the other vendors implement ring protection, but these models
also do other things you might want your network to have (QinQ,
per-VLAN controls).
Rubens
> I am in process of planning ring network to cover 15 POPs in City.
> Some technologies are chosen for consideration like SDH(Huawei),
> PVRST+(Cisco), RSTP(Zyxel), EAPS (extreme network) and MPLS(VPLS).
> The purpose is to provide L2 Ethernet connectivities from POPs to
> central point (DC) and ring protection.Of the above, VPLS.
Strongly disagree. VPLS gives you ample rope to hang yourself. An L2
ring-based protocol like EAPS is much simpler to deploy.
Steinar Haug, Nethelp consulting, sthaug@nethelp.no
What is EAPS?
Rod Beck wrote:
What is EAPS?
A joke of a "standard" and something to be avoided at all costs. I would echo the last part about Extreme switches too.
Justin
Since it was brought up - curious as we were recently approached by
Extreme. Good/bad experiences? We're a Cisco shop and I plan to keep
us that way but some "powers to be" are interested in them at this
point..
Thanks,
Paul
Rod Beck wrote:
> What is EAPS?A joke of a "standard" and something to be avoided at all costs. I
would echo the last part about Extreme switches too.
Disagree. I don't believe anybody would claim EAPS is a "standard"
just because an RFC has been published. In any case, EAPS is working
quite well for us, with rapid L2 rerouting in ring based structures.
And *much* simpler than RSTP/MST. Or VPLS, for that matter.
As for Extreme switches - they have their strengths and weaknesses,
just like any other product. We use lots of Summit X450/X450a, for
L2 only, and have been generally reasonably happy with them. If I
could buy a similarly featured product from Cisco, for a similar
price, I might well choose Cisco. But at least in our case Cisco
*doesn't* have a competitive product (case in point: ME3400 - too
few ports, too few MAC addresses, funky licensing even if you just
want to do simple QinQ).
Steinar Haug, Nethelp consulting, sthaug@nethelp.no
sthaug@nethelp.no wrote:
Rod Beck wrote:
What is EAPS?
A joke of a "standard" and something to be avoided at all costs. I would echo the last part about Extreme switches too.
Disagree. I don't believe anybody would claim EAPS is a "standard"
just because an RFC has been published.
Pannaway does. That was one of the very arguments I used against their product when they were brought in. They claimed that it was a standard because it had a RFC. I tried to explain the difference between an Information RFC and a Standards Track to no avail. Of course this also came from the Pannaway SE that gave me 3 quotes I repeat as often as possible to as many people as possible. He said:
1) that we didn't need to run an IGP across our network because we weren't big enough to need one. This was in response to my query about their lack of support for IS-IS. He said that he'd seen SP networks many times our size get by perfectly well with static routes.
2) that we didn't need QoS on our network if our links weren't saturated. I won't get into the holy war over serialization delay, micro bursts, and queuing here. It's been hashed out many times before on NANOG I'm sure.
3) that IPv6 was just a fad and that it would never be implemented in the US. I got our /32 in 2008 and am working on the deployment now. I'm certainly not breaking new ground here either. It may not be the most common thing in the US but it is picking up steam for everyone not running Pannaway products since they don't support IPv6 (the BASs and BARs that we ended up buying at least).
As for Extreme switches - they have their strengths and weaknesses,
just like any other product. We use lots of Summit X450/X450a, for
L2 only, and have been generally reasonably happy with them. If I
could buy a similarly featured product from Cisco, for a similar
price, I might well choose Cisco. But at least in our case Cisco
*doesn't* have a competitive product (case in point: ME3400 - too
few ports, too few MAC addresses, funky licensing even if you just
want to do simple QinQ).
I don't have any experience with the ME3400 unfortunately. A mix of vendors isn't a bad thing if you have the knowledge, depth and time to keep up with each of them so you can support the device adequately (adequate staffing is involved here too). When one buys a budget switch just to save a few bucks they tend to get what they paid for and none of what they didn't (training, experience for their staff, printed third-party references, reliable online support groups for example).
I'm in a situation right now where a vendor has proposed a basic L2 switch solution to redundantly connect 2 of our sites. They come in cheaper than the Cisco equivalent (4 4948-10GEs) but we also have absolutely no experience with that vendor. That means interopt testing, future finger pointing in the heat of an outage, double training staff, inevitable config errors and typos thanks to the differences between the vendor we're used to and the one that is being proposed for this one-off connection. The better fool-proof solution costs a bit more and I have to convince management not to save a short-term buck which costs of many long-term bucks. Sometimes you really do get what you pay for.
Justin
Does anyone have best practise for implementing those technologies ?
I am currently doing a testing LAB with CISCO REP since i have a few Metro on hand.
It works quite well in my LAB. There is one Request Time Out if the link break BUT it is physical layer not REP 
An additional requirement often overlooked by Metro Ethernet architects
is to ensure that layer 3 multicast stateful protocols are implemented
in the carrier equipment. In order to ensure that PIM (S,G) stateful
packets are not flooded out all ports in customers'
geographically-dispersed switches, PIM snooping must be implemented in
the carrier's equipment. Otherwise, the carriers' Metro Ethernet service
operates like a 1990's-style shared hub incorrectly flooding (S,G)
packets. For customers that have constant 10+ Mbps (S,G) multicast
streams, the absence of PIM snooping effectively renders 10+ Mbps ports
useless.