Hssi Connections; Equipment Racks - Cisco 7000 Hardware Installation And Maintenance

Site Requirements
For Further Reference
The following publications contain information on determining attenuation and power budget:
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HSSI Connections

The High-Speed Serial Interface (HSSI) standard (EIA/TIA 612/613) specifies a maximum cable
length of 50 feet (15 meters) for 52 Mbps HSSI connections. The typical (nominal) cable length
between the HIP and the DSU is 6 feet (2 meters). The HSSI interface cable comprises 25 twisted
pairs and a 50-pin plug at each end. Both DTE and DCE ports on the HIP and the DSU are 50-pin
receptacles. The HSSI interface cable is similar to a SCSI-II-type (small computer systems interface)
cable; however, the HSSI cable specification is more stringent than that for a SCSI-II. Substituting
a SCSI-type cable to connect the HSSI interface may prevent proper operation of the interface.

Equipment Racks

An optional rack-mounting kit is available for mounting the router in a standard 19-inch equipment
rack. The mounting kit is not suitable for use with Telco-type equipment racks, or those with
obstructions (such as a power strip) that could impair access to the interface processors and power
supplies. In Telco environments or at installation sites that use nonstandard racks, the router can be
mounted on an equipment shelf, provided that the rack dimensions allow safe installation and access
to the power supplies and interface processors. Figure 2-3 show the chassis footprint and outer
dimensions.
To use the optional rack-mount kit, your equipment rack must meet the following requirements:
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When planning your rack installation, consider the following guidelines:
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2-80 Cisco 7000 Hardware Installation and Maintenance
T1E1.2/92-020R2 ANSI, the Draft American National Standard for Telecommunications
entitled "Broadband ISDN Customer Installation Interfaces: Physical Layer Specification."
Power Margin Analysis, AT&T Technical Note, TN89-004LWP, May 1989.
The width of the rack, between the two front mounting strips or rails, must be 17 3/4 inches.
The depth of the rack, between the front and rear mounting strips, must be at least 19 1/4 inches
but not more than 32 inches.
The height of the chassis is approximately 20 inches (19 1/4 inches when the chassis feet are
removed). The rack must have sufficient vertical clearance to insert the chassis and, if required
after installation, to remove the chassis feet.
If the rack has a vertical power strip or other potential obstacle, ensure that it will allow sufficient
clearance to install and remove both interface processors (11 inches deep) and power supplies
(16 inches deep), both of which must be pulled straight out of the chassis. (See Figure 2-3.)
Allow at least 3 to 4 feet of clearance behind the rack for maintenance. If the rack is mobile, you
can push it back within one foot of a wall or cabinet for normal operation and pull it out when
necessary for maintenance (installing or replacing interface processors or power supplies, or
connecting network cables or interface units).
The ports for cooling air are located on the front and rear of the chassis, so multiple routers can
be rack-mounted with little or no vertical clearance. However, avoid placing the router in an
overly congested rack.
Consider the equipment and cabling that is already installed in the rack. Ensure that cables from
other equipment will not obstruct the airflow through the chassis or impair access to the power
supplies or interface processors. Route cables away from field-replaceable components to avoid
having to disconnect cables unnecessarily to perform equipment maintenance or upgrades.