All, I was speaking to a friend who works for foundry about their new XRMON capable devices. He forwarded this post from the NANOG list and I was wondering if anyone is already addressing some of these issues. I got to looking at their sFlow (rfc 3176, www.inmon.com/its ) MIB extensions for realtime traffic accounting and utilization gathering which seems to be very impressive. Also, what are some of the implications of real time traffic engineering with MPLS and the possiblity of creating automated billing for traffic throughput withn the network. I've got quite a bit of reading to with the whitepapers for RMON, SFlow, and NetFlow.
Howard, I really like to hear your thoughts on this.. :-> Here's the post from the NANOG. -Nigel -----Original Message----- From: srihari varada To: [EMAIL PROTECTED] Subject: MPLS in metro access networks Hello: I have heard some stressing the role of MPLS in metro access networks. It is difficult for me to visualize the need for it in them while it is not so difficult to understand the utility (load balancing and fault restoration etc.) of it in the metro backbone networks. To characterize metro access networks in the context, the following is provided: -- aggregates traffic from residential (arriving via broadband access links such as xDSL, Cable) and business consumers (arriving via broadband access links such as xDSL and high speed links such as Ethernet or SONET) -- funnels aggregated traffic to metro backbone networks for destination hosts in the local metro region or remote regions across the internet regional and backbone networks. Majority of such access networks are SONET/ATM based (I didn't come across any case of Gig Ethernet. However, I do not preculde it). Thus, there are two questions: -- Are there known RBOCs/ILECs and CLECs entrenching MPLS in the said network scope? (I do not see many major ILECs in the un-official MPLS service providers list being circulated but it may mean little) -- If so, what motivates them to do so? Any analysis of the driving forces is appreciated. Regards, Srihari Varada From: On Behalf Of Quibell, Marc Sent: Thursday, November 15, 2001 10:20 AM To: 'srihari varada'; [EMAIL PROTECTED] Subject: RE: MPLS in metro access networks I would think faster switching/routing and less processing would be wanted in any mid-to-large sized network...I'm not sure what load balancing and fault restoration has to do with MPLS.... Marc From: Michael Cohen Sent: Thursday, November 15, 2001 10:45 AM To: [EMAIL PROTECTED] Subject: RE: MPLS in metro access networks And I'm not sure what faster switching/routing has to do with MPLS:) I believe one of the ideas behind MPLS benefiting metro access networks is using MPLS to deliver layer 2 VPNs across an MPLS enabled core thus simulating leased lines for access clients...but I'm sure somebody will correct me if I'm wrong. There seems to be some hype for Martini draft VPNs and large enterprise customers in metro areas. Cheers, -Michael Cohen From: Quibell, Marc [] Sent: Thursday, November 15, 2001 12:04 PM To: '[EMAIL PROTECTED]' ; [EMAIL PROTECTED] Subject: RE: MPLS in metro access networks I guess you answered your own question: "And I'm not sure what faster switching/routing has to do with MPLS:)" As far as CEF and such goes, I couldn't disagree with that (as I was not comparing MPLS to other optimized forwarding techniques), however, MPLS is not a vendor-proprietary forwarding mechanism, which means that I can deploy it worldwide, or state-wide, whatever the case may be, in my network and have the benefit of using only ONE protocol with MPLS-enabled/aware routers/switches. A definate plus over the other proprietary fast switching techniques you mentioned. Your last statement indicates "added services" have nothing to do with the fast switching processing of MPLS, when in fact these services depend upon the faster delivery of the non-proprietary fast switching of MPLS. As quoted from the rfc Marc From: Behalf Of Michael Cohen Sent: Friday, November 16, 2001 3:45 AM To: [EMAIL PROTECTED] Subject: RE: MPLS in metro access networks Maybe I'm getting confused. The original post asked the question "what motivates them" (RBOCs, ILECs, and CLECs) to implement MPLS. You answered that fast switching/routing was a reason. I disagree with this because designing and implementing MPLS just for speed benefits is a bit too cumbersome and complex compared to using local caching mechanisms that are just as fast, if not faster. Saying that using MPLS as an alternative to using local caching mechanisms because of standardization doesn't make sense to me either because the local caching mechanisms are in place regardless. In fact, you can't run MPLS on most vendor hardware without running their proprietary caching (Cisco mandates using CEF before implementing MPLS and Juniper uses it's FPC hardware architecture regardless of MPLS). So to add to my point, there is no speed benefit in running MPLS if you are already using modern caching techniques, which most service providers interested in MPLS are already doing. To respond to your second point regarding using added services I agree completely that these services require MPLS labels to work. However, this still has nothing to do with speed benefits. You say "these services depend upon the faster delivery" of MPLS but the RFC doesn't mention speed at all. It just says "This approach uses MPLS running in the backbone to provide premium services". Any MPLS added service uses label stacking which allows for the RFC stated "premium services". Cheers, -Michael Cohen >From On Behalf Of Gary Blankenship Sent: Friday, November 16, 2001 5:34 PM To: [EMAIL PROTECTED] Subject: RE: MPLS in metro access networks Srihari: I'm going to attempt to answer your original question: -- If so, what motivates them to do so? Any analysis of the driving forces is appreciated. All: I've been consulting MPLS solutions for service providers here in Asia. The main reason for running MPLS is traffic engineering. The main reason for desiring traffic engineering is because of the hyper-aggregation problem with the routing protocols. I talked to one provider who was obviously stressed and showed emotion when addressing this problem. Basically, they appeared just shy of desperate. You also have more flexibility separating the data and control planes. Remember that the control plane (RSVP, IP Telephony, IBGP sessions across the network core) follows the same best path(s) as the data plan. Fortunately for RSVP, you can strict and loose route to avoid this problem. I assume this is important because RSVP is how you signal the LSP's to solve the original problem! You can engineer each plane and classify flows into Forward Equivalency Classes (FECs). Think of the example I will post below as the endpoints to the L2 VPN going towards the Virtual Circuit (VC FEC). WARNING: Traffic Engineering can create more problems than it solves if you do not engineer correctly. Data collection BEFORE traffic engineering is essential. You should enter step 2 (configuring TE) with full understanding of your network. How do I apply this in a metro access network? Before we talk about MPLS, let's talk about a metro network that uses Super VLAN Aggregation (not standardized, Foundry and Extreme support as well as other vendors who I apologize for not mentioning if they do. If you work for one of these vendors please let me know so I can tell my customers who our competitors are :-). You can traffic engineer using 802.1s STP groupings, but you have scalability limitations (12 bits of VLAN ID in .1q tag) of 4096x4096. This is an excellent solution with all of the other enhancements such as 802.1w (Rapid Spanning Tree for failover times of less than 5 seconds and as fast as 50ms). Additionally, vendor proprietary standards help out such as Foundry's Super Span for segregating STP domains and tunneling BPDU's to arrive where they should. Now let's talk about MPLS. Most of you are smarter than I and familiar with Cisco IOS. Foundry uses a similar flavor of the CLI (like different UNIX versions :-) I'll drop a config on how you can engineer 4 VLANS through your network. The users think they are on the same Ethernet wire (Ethernet Psuedo Wire End-to-End Encapsulation). One LSP transmits and one LSP receives (full duplex). The technology involved is simple Layer2 VPN Draft Martini. It is only point to point and this is not the forum to discuss the ever evolving standards that are competing; however, the Martini drafts are mature and I believe ready to reach informational RFC status very soon. I don't believe the market (NANOG folks reading this message for example) wants the complexity of running BGP on L2 or L3 VPNs. This is why you won't find too much support for the new draft Kompella (not to be confused with the developing VPLS draft VKompella). Juniper showed a configuration slide of this at MPLS Japan last week (original draft recently released and not mature "00" with no revisions and missing information). I would request someone from Juniper post a configuration to this list showing my same example with Kompella support for complexity comparison. If I were a Juniper customer already running L3 VPN I would take a serious look at this. It reduces the complexity a bit, but not enough for my liking. Everyone agrees that separating MAC address learning is essential for solving MAC address scalability requirements. Targeted LDP sessions appear to be a lot less complex than BGP and we may see some solutions arrive soon. The Martini drafts got the LDP targeted sessions covered nicely. I'm an SE who reads NANOG to help better understand my customers' problems. I'm not a developer and I'm not caught up in the whirlwind going on in the MPLS WG or back in San Jose. I'll leave that task to smarter folks with better access to Starbucks. I also encourage you to take a look at using Super VLAN technology with an MPLS core to solve scalability problems when you want the best of both words. Example Terminology: LSP: Label Switched Path that uses the tunnel label. Signaled and setup through RSVP in this example. VLL: Virtual Leased Line that uses the VC label. OSPF-TE: Opaque LSA support. Note that I've configured and I HIGHLY recommend you do this whether you use CSPF or not. "show ip ospf database link opaque" can be an awesome command and I believe it is the same on Cisco IOS. For those of you that have this ability and understanding, you may want to generate these LSA's regardless of your plans for MPLS. Hot standby paths: Pre-signaled RSVP paths for faster failover in this example. My example also uses statically defined VC label definitions. This brings up the VC as soon as the LSP route comes up (show mpls route) and reduces convergence time by eliminating the need for targeted LDP overhead. NOTE: Consider this L2 VPN complexity that can be eliminated if you think it is too complex to manage. These are the values you see after the vll-peer statements. I will demonstrate the mixing and matching of tagged 802.1Q lines as well. We have a topology as follows: B A_/ _D / C Please don't give me any feedback of "Why" I would run MPLS on such a simple network. It is meant for simplicity only. Note that these are working configs for the folks that knock MPLS for configuration complexity. I cannot speak for other vendors. You would also need our latest and greatest code (7.5.00) which is not available to our non beta customers until next week. I've included configs for B, but not C. I'm sure you can all figure out C. -------------------------------------------------------- hostname A router mpls policy traffic-eng ospf mpls-interface p2/1 mpls-interface p2/2 path B-to-D strict 192.168.10.2 strict 192.168.20.1 path C-to-D strict 192.168.30.2 strict 192.168.40.1 lsp LSP1 to 192.168.50.1 primary B-to-D secondary C-to-D standby enable lsp LSP2 to 192.168.50.2 primary B-to-D secondary C-to-D standby enable lsp LSP3 to 192.168.50.3 primary B-to-D secondary C-to-D standby enable lsp LSP4 to 192.168.50.4 primary C-to-D secondary B-to-D standby enable vll VLAN10 10 vll-peer 192.168.50.1 800001 900001 vlan 10 tagged e 1/1 vll VLAN20 20 vll-peer 192.168.50.2 800002 900002 vlan 20 tagged e 1/1 vll VLAN30 30 vll-peer 192.168.50.3 800003 900003 vlan 30 tagged e 1/1 vll VLAN40 40 vll-peer 192.168.50.4 800004 900004 vlan 40 tagged e 1/1 ! boot sys slot1 N2M07500.bin route-only router ospf area 0 ! interface loopback 1 ip address 192.168.5.1 255.255.255.255 ip ospf area 0 interface loopback 2 ip address 192.168.5.2 255.255.255.255 ip ospf area 0 interface loopback 3 ip address 192.168.5.3 255.255.255.255 ip ospf area 0 interface loopback 4 ip address 192.168.5.4 255.255.255.255 ip ospf area 0 ! interface ethernet 1/1 enable ! interface pos 2/1 enable ip address 192.168.10.1 255.255.255.0 ip ospf area 0 ! interface pos 2/2 enable ip address 192.168.30.1 255.255.255.0 ip ospf area 0 ! ! ! ! ! end -------------------------------------------- hostname D router mpls policy traffic-eng ospf mpls-interface p2/1 mpls-interface p2/2 path B-to-A strict 192.168.20.2 strict 192.168.10.1 path C-to-A strict 192.168.40.2 strict 192.168.30.1 lsp LSP1 to 192.168.5.1 primary B-to-A secondary C-to-A standby enable lsp LSP2 to 192.168.5.2 primary B-to-A secondary C-to-A standby enable lsp LSP3 to 192.168.5.3 primary B-to-A secondary C-to-A standby enable lsp LSP4 to 192.168.5.4 primary C-to-A secondary B-to-A standby enable vll VLAN10 10 vll-peer 192.168.5.1 900001 800001 untagged e 1/1 vll VLAN20 20 vll-peer 192.168.5.2 900002 800002 untagged e 1/2 vll VLAN30 30 vll-peer 192.168.5.3 900003 800003 untagged e 1/3 vll VLAN40 40 vll-peer 192.168.5.4 900004 800004 untagged e 1/4 ! boot sys slot1 N2M07500.bin route-only router ospf area 0 ! interface loopback 1 ip address 192.168.5.1 255.255.255.255 ip ospf area 0 interface loopback 2 ip address 192.168.5.2 255.255.255.255 ip ospf area 0 interface loopback 3 ip address 192.168.5.3 255.255.255.255 ip ospf area 0 interface loopback 4 ip address 192.168.5.4 255.255.255.255 ip ospf area 0 ! interface ethernet 1/1 enable ! interface pos 2/1 port-name NI800_D_POS_3/1 enable ip address 192.168.40.1 255.255.255.0 ip ospf area 0 ! interface pos 2/2 port-name NI800_D_POS_3/2 enable ip address 192.168.20.1 255.255.255.0 ip ospf area 0! ! ! ! ! end ------------------------------------------------- hostname C router mpls policy admin-group OSPF-Primary-Link 2 traffic-eng ospf mpls-interface p6/1 admin-group 2 mpls-interface p6/2 admin-group 2 ! boot sys slot1 N2M07500B5.bin route-only router ospf area 0 ! interface pos 6/1 enable ip address 192.168.40.2 255.255.255.0 ip ospf area 0 ! interface pos 6/2 enable ip address 192.168.30.2 255.255.255.0 ip ospf area 0 ! ! ! ! ! end Gary Blankenship Foundry Networks Systems Engineer - Japan CCIE #5009 www.foundrynet.com PC Magazine Selects Foundry FastIron 4802 as Best High End Ethernet Switch: http://www.pcmag.com/article/0,2997,s%253D25109%2526a%253D17629,00.asp > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=26593&t=26593 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
