Skip to Content

Core Router Equipment Arrived, Installation Notes

Printer-friendly versionPrinter-friendly version

The new Nexus 7010 core routers arrived last week. These boxes are large and heavy, weighing around 400lbs and approximately 37" tall and 38" deep. We have a pair of furniture dollies to help move them around, and a lift table to position them for installation in the cabinets; please feel free to contact if you're unfortunate enough to need to borrow the dollies or lift table for your projects.

The routers support up to three power supplies, each with two inputs; 220VAC is preferred, though they can use 120VAC. The plan is two use two power supplies, with one 220VAC input to each supply coming from an APC UPS (with generator power, excluding North Hall at the moment) and the other 220VAC input from commercial power. This is sufficient to power the current line cards in the event of a power suppy, UPS or single source failure. Power will be distributed via two APC AP7941 rackmount PDUs, one for commercial power and the other for UPS power.

Out-of-band (OOB) management on the current Cisco 6506 routers is via serial ports accessed across phone-line copper. This was typically used as a backup during software upgrades and to troubleshoot during major disruptive outages. The new routers still have serial console ports, but the new core will use a dedicated, ethernet-based OOB system. This is a big help during diagnostics, when "show tech" diagnostic output takes a long time over a 9600-baud serial line. The OOB switches are partially configured and should be ready for installation by the end of the week.

The current Cisco 6506 routers are installed in old Bud Industries cabinets, which were never particularly appropriate for this gear. These Bud cabinets are narrow, which forced cabling directly in front of the equipment mounting rails and limited side-to-side airflow used to cool the routers. The 7010 uses front-to-back airflow, but new cabinets were still required to address cable routing and management, as well as the significantly increased depth of the routers. After reviewing several manufacturers, we'll use the APC AR3350 cabinet, which provides 42U of space in a footprint approximately 30" wide and 48" deep. The height is common to other cabinets and should fit well in most locations, including the North Hall Data Center. The depth is a bit challenging, particularly since at least 34" front clearance is required to install the routers.

The planned cabinet layout, starting at the bottom, will use 9U for UPS and battery packs, 1U reserved, 21U for the 7010, 1U reserved, 1U cable rings for fiber, 2U media converter chassis, 2U cable rings for copper, 1U Cisco 2960 building switch, 1U reserved, 2U cable rings for copper, and 1U Cisco 2960 OOB management switch. All network cables enter through the roof at the front of the cabinet, with copper on the left and fiber on the right. Every effort will be made to ensure these cables never cross each other. All of the new fiber jumpers will have 2mm-jackets or smaller, rather than the 3mm jackets commonly seen in panels today; this permits greater cable densities and is commonly deployed in data centers.

Initial configuration of the 7010 boxes has begun. I only have a couple of power cords (5-15P to IEC C19), which is just enough to bring up the supervisor modules; additional cords are on order and will boost the power to run the line cards. Meanwhile, site preparation is slowly moving forward. Each core location is unique, but they all need electrical work. Finding a footprint for each cabinet varies from simple to nearly impossible, and one location needs additional ventilation.

Migration will undoubtedly be disruptive, and it should be assumed that each core location will have to be migrated over several hours. Power should be ready and jumpers staged to help smooth the migration, but otherwise a location migration may involve fiber panel relocations, complete removal of old equipment, use of a reciprocating saw to remove the old cabinet, installation of the new cabinet (e.g. bolting to floor), installation of new equipment, etc.