JUNOS had been a modular OS since day one. Cisco had a monolithic OS from day one which gives downtimes. Cisco hired few people from Juniper and adopted their “best practices” into their crappy IOS.
What Juniper has to say about it:
Juniper is often not one to discuss with the media its thoughts on the competition when the competition – i.e. Cisco – makes a big product announcement. However, this week, Juniper CTO and founder Pradeep Sindhu told exactly what he thought of Cisco’s new ASR 1000 router, namely how wrong Cisco is to force its customers to learn a new operating system with each new product (ASR 1000 sports the new IOS-XE, and the Cisco Nexus data center switch has the new NX-OS).
In a Q&A with Duffy, Sindhu said: “[A single operating system] is a need that our customers are telling us they have. They do not like the fact that they have to read manuals this thick to figure out what release of the operating system works with which particular product and products, and what the combination of limitations are that are imposed by particular subsets of the products that they are using. That becomes very complicated. Much of this is reflected in operational cost increasing for the customer.”
He said this is in sharp contrast to Juniper’s strategy of having a single OS and a single architecture. “We try to have a consistent single operating system and a single unified architecture for two reasons: internally [at Juniper], it is tremendously efficient because we get to solve difficult problems once rather than solving them over and over again; from a customer’s standpoint products appear to be consistent and are consistent, so they are a lot easier to use.”
Makes sense to me. But why is it that Cisco is coming out with a new OS with each new significant product?
The Technology cisco adopted:
IOS XE runs on the new generation of ASR routers. These are again aimed at service providers, but also at large enterprises looking for very high throughput edge devices. IOS XE is based around a Linux Kernal with IOS features being ported in from ond of the conventional IOS 12.2SR release trains. It is more modular (although conventional IOS is heading this way too) and thus should be more stable as a single process failing should not cause the whole router to fall over as happened on older IOS releases. Very different types of ASIC and FPGA are used on the ASR’s necessitating the different OS.
NX OS is run on the new Nexus 7000 and 5000 series switches. These sit above the Catalyst 6500 series in terms of performance and are aimed at large datacentres, offering the ability to unify your SAN, LAN, WAN and Security infrastructure to a much larger extent with new technologies such as Fibre Channel over Ethernet. The OS includes much of the 12.2 IOS features, some things ported from SAN-OS (runs on some of the data switches) and some new stuff which Cisco got when they bought the company that originally made these switches.
The main reason for the seperate software releases in each case is because the processing/fabric is far more distributed then in traditional routers and switches, with very different chipsets used requiring different processes to handle it.
In addition to this some of the new OS’s have come from purchases Cisco has made, much as happened with PIX and Catalyst switches (which used to run CatOS and not IOS).
Cisco’s plan for the future:
Cisco’s traditional IOS is based on QNX which is a Unix-based real-time OS and so is IOS-XR, the difference being that IOS-XR has more modularity while traditional IOS is monolithic. By monolithic I mean that the entire software is compiled into a single image that is loaded into memory so any upgrades/patches etc need downtime for the device. With IOS-XR you can upgrade portions of the OS without bringing down the entire device and hence its much more suitable for critical systems.
Traditional IOS will in due course be replaced with modular IOS but not with the QNX-based IOS-XR. Cisco is using a different version of IOS on the ASR router called IOS-XE and on the Nexus switch (an upgrade of SAN-OS) called NX-OS. Both are based on a linux kernel from Montavista Linux, and they are fully modular just like IOS-XR. Ultimately, most mainstream Cisco platforms will run something like IOS-XE.
IOS-XR is currently used only on the CRS routing platform (used for very large service provider core, not enterprises) and is likely to stay that way.
So to answer your question – No, IOS-XR per se will probably not be widely used across Cisco’s product line. But modular OS in the form of IOS-XE type software will be what Cisco pushes in the future.
The modular features of IOS XE and the ASR are a critical factor for Jeff Young, CTO of FactSet Research Systems Inc. FactSet supplies historical and real-time financial analytics to financial institutions worldwide and has POPs around the globe. “One hundred percent uptime is critical for our customers, and therefore critical for us,” Young says. “A single POP could have hundreds of clients relying on it to access real-time and analytical data services. Any downtime impacts our clients’ business. In-service upgrades of SPAs and IOS keep our network running without disrupting our infrastructure.”
Leveraging the 40-core Quantum flow processor (announced by Cisco in February and which can process 160 simultaneous threads at a whopping 49 billion transactions per second), the ASR supports the common services found on Cisco’s routers, including stateful firewalling, QoS, VPN, and multicast. In addition, it supports leading-edge services like deep packet inspection for application performance management, a session border controller for VoIP, performance routing, as well as a platform for additional services. Services can be added to IOS XE, and the company is working internally to identify additional services. Cisco doesn’t have any immediate plans to open the platform up to third-party developers but is leaving the door open for future external development.
The increased capacity and processing power of the ASRs make them a good replacement for multiple Cisco 7200 or 7300 routers in service today. Consolidating multiple platforms saves rack space and power requirements. Cisco estimates an ASR is twice as efficient compared with the number of routers required to support the same performance requirements. That’s good for the environment, but also good for the bottom line. “Since we use co-location space in POPs around the globe, we pay by the rack unit and watt. Any reduction in space and power while maintaining our quality guarantees adds to our bottom line,” FactSet’s Young says.