""dre"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > ""Priscilla Oppenheimer"" wrote > > I may be starting a new project doing some writing about > > technologies used in enterprise networks. (read not service > > provider) > > > > Do I need to cover IS-IS? Or is it mainly ISPs that use this? > > I've never seen IS-IS in Enterprise networks, only ISP > backbones and CODCN's (Central Office Data > Communications Networks) that implement OSI stacks on > network elements. The primary reason I've heard (I'm an > IS-IS fan working in the Enterprise), that also happens to > be a sort of compelling argument - is that OSPF and > EIGRP work better through firewalls. I believe that IS-IS > is significantly less complex than OSPF or EIGRP, and > therefore, easier to train/learn, implement, manage, etc.
I've seen ISIS used by enterprises on occasion. ISIS has more tuning parameters and more extensibility than OSPF. It also has significantly more scalability than OSPF. I dislike EIGRP precisely because it's inner-workings are closed. > > > How about MPLS? I should discuss it briefly, but aren't > > the main users of MPLS ISPs, not enterprise networks? > > I've only seen MPLS in ISP networks, but could be used > in Enterprise, especially simple VRF concepts (from > MPLS VPN's). I could see many reasons that Enterprises > could use even static route VRF's for various useful purposes > on occasion, but even that is a rarity. Of course, I'm also of > the opinion that MPLS doesn't really belong in SP networks > either - so YMMV. MPLS-TE is still being argued among > the SP network guru's. MPLS FRR (Fast Re-Route) is an > important network protection and resliency technology and > should be researched, tested, and implemented when the > need arises for it (including for Enterprises). True, MPLS is rarely used in the enterprise, although again, I have seen it on occasion. I am convinced that MPLS will indeed become the next big thing in SP's, but not the flavor of MPLS the way it is constructed now. In particular, I see RFC2547 and MPLS-TE as being only minor considerations in the future for MPLS implementation (granted, they are the major reasons now). Instead, I think that MPLS will ultimately morph into a generalized technology by which providers will be able to offer a complete range of services and features using a unified (dare I say 'converged'?) network. In particular, the day that MPLS can offer a complete range of ATM/FR/voice services without forcing a wholesale migration to IP from legacy gear is the day that widespread MPLS migration will occur. Anticipation of this has already occurred - providers are now unwilling to invest in legacy ATM gear because they are hoping that MPLS will be fully baked in the next few years. MPLS will also, through its GMPLS offshoot, be able to offer important network management advantages. Therefore, sorry to say it, but I see things like RFC2547 and MPLS-TE as only sideshows to the 'real' MPLS initiatives - ATM interworking, circuit-emulation style technologies like the Fischer draft, GMPLS, and the like. RFC2547, in particular, I see as a quite dangerous sideshow because of its implication to BGP scalability and stability. > > > Anyone using GARP? That's on my list to research too. > > GARP, as in Multicast? Many Enterprises are using > Multicast, but their use can vary depending on the > company (could be for reliable multicast like TIBCO, or > could be for live broadcasting sending/receiving, or > research, or many other technical/business reasons). > Understanding the basics is good, but it's hard to cover > all the advanced topics in IP Multicast because it's such > a point application as it is already. GARP is not widespread at the moment. > > > Alas, I have a lot to learn. Thank-you VERY much > > for answering these quick questions. > > You will probably want to look at this from a specific industry > perspective, i.e.: > > High-Tech Manufacturing / Hardware/Software Engineering > Pharmaceuticals > Automotive, Consumer Goods > Government / Political / Federal vs. State/County/City > Defense / Military / Aerospace > Education > Banking / Securities / Financials / Real-Estate > Insurance Companies > Entertainment > Retail > Health Care > Hospitality / Transportation > Energy > > Certain companies have totally different needs technology-wise... > in particular, some business build networks without latency in mind > because they are a state-wide organization, or even a city-wide > organization. Some companies have networks that span the globe, > and some have the same type of need in a mission-critical way. > There are many technologies that apply to certain companies and > not others. > > For any large Enterprise that relies on IT to be mission-critical, > figure that the cost of IT downtime is significant (Meta Group > 2001 report shows $1.5M per hour of downtime). IT relies on > the Internet for growth and technology. Data centers, especially > Internet data centers are the key point to any IT infrastructure. > The primary technologies in these environments are rapidly > shifting. Many organizations are now required to, or at the very > least are planning to, add more than one primary data center for > 100%, near-instantaneous continuous operation / disaster > recovery. You will see this in the High-Tech industry because > of maturity, and you will see it in the Government/Defense > industries because of things like the Homeland Security Act > (signed November 25th, 2002). The same Meta group report > shows that 70-75% of mid- to top-tier applications will be > distribued across at least two data centers by 2003. I got this > information from: > http://www.cisco.com/global/EMEA/networkers/presentations/NSC-284_Reiner_Dre > sbach.pdf.gz > That's a nice summation of where technology is going. But I would add that you shouldn't fixate yourself on the Internet. Technologies are converging towards IP, but not necessarily the Internet, nor should it. After all, let's face it, the Internet as a whole is a money sink, especially to the provider. Few carriers in the world have actually figured out how to make profit off the Internet and there are few if any truly credible ways I've seen that allow the carriers to ultimately make profit. Therefore, according to the laws of corporate finance, there will be less and less investment by carriers in Internet infrastructure (notice that I didn't say IP infrastructure, I said Internet infrastructure). Makes perfect sense too - if you kept losing money at something, would you keep doing it? Therefore I can see a world where the Internet itself becomes less and less reliable over time - certainly not something you would entrust the operation of your enterprise. Instead, what I think we'll see is the rise of large-scale private IP networks that are not connected to the Internet (or at least, shielded from the Internet via superfirewall/superNAT's/superproxies), and these networks will be the basis for offering services like disaster recovery, storage, voice, and the like. It is only with private IP networks that you will be able to offer the kind of quality-of-service, security, and privacy that enterprises want (and get today via ATM/FR/leased-line services which, unlike the Internet, are actually profitable). Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=58583&t=58493 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
