Page 2 - Important Information; This section contains information about the following topics:; Ethernet Line Card Product Numbers; Supported Platforms; lists the supported router platforms for Ethernet line cards:; Ethernet Line Card
2 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Important Information Important Information This section contains information about the following topics: • Ethernet Line Card Product Numbers, page 2 • Router Hardware Installation, page 2 • Cisco IOS Software Release and Har...
Page 3 - Note; Cisco IOS Software Release and Hardware Revision Requirements
3 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Important Information Note The Cisco XR 12000 Series Routers must have a full set of switch fabric cards installed to support the requirements of the Ethernet line cards. See the appropriate Cisco 12000 Series Router installat...
Page 4 - Memory Options; Ethernet line card memory options vary by line card. See; Related Documentation; See the; Product Overviews; -Port Gigabit Ethernet ISE Line Card, page 5; Ethernet Line Card Comparison
4 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Product Overviews Memory Options Ethernet line card memory options vary by line card. See “Line Card Memory” section on page 65 for more information. Related Documentation This publication describes the basic installation of a...
Page 5 - Caution; -Port Gigabit Ethernet ISE Line Card
5 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Product Overviews Caution To prevent system problems, do not use Gigabit Interface Converters (GBICs) from third-party vendors. Use only the GBIC that shipped with your Ethernet line card. The GBIC might contain an internal EP...
Page 6 - For more information, refer to the; Part Number
6 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Product Overviews Table 5 summarizes the optics and connectors used by the 4-Port Gigabit Ethernet ISE line card. For more information, refer to the “Gigabit Ethernet SFP Modules” section on page 48 and the “Cabling and Specif...
Page 9 - Preparing for Installation; Safety Guidelines, page 9; Safety Guidelines; Preventing Electrostatic Discharge; The following are guidelines for preventing ESD damage:
9 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Preparing for Installation Preparing for Installation The following sections provide information about preparing to install line cards: • Safety Guidelines, page 9 • Preventing Electrostatic Discharge, page 9 • Required Tools ...
Page 10 - Warning; Required Tools and Equipment; Removing and Installing a Line Card; Guidelines for Line Card Removal and Installation, page 11
10 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing a Line Card • Avoid contact between the Ethernet line cards and clothing. The wrist strap protects the board from ESD voltages on the body only; ESD voltages on clothing can still cause damage. Warning...
Page 11 - Guidelines for Line Card Removal and Installation; shutdown; command before removing a line card.; configure; Removing a Line Card; Figure 4
11 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing a Line Card Guidelines for Line Card Removal and Installation Guidelines for line card removal and installation include the following: • Online insertion and removal (OIR) is supported, enabling you to...
Page 12 - Detach the line card cable-management bracket from the line card.
12 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing a Line Card Step 2 Disconnect and remove all interface cables from the ports; note the current connections of the cables to the ports on the line card. Step 3 Detach the line card cable-management brac...
Page 13 - Installing a Line Card
13 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing a Line Card Caution Be careful not to damage or disturb the EMI spring fingers located on the front edge of the card face plate. Note Always insert a dust plug in an optical port opening for each port ...
Page 15 - “Verifying and; Removing and Installing EPAs; Inserting an EPA into a Modular Gigabit Ethernet Line Card, page 17; Removing an EPA from the Modular Gigabit Ethernet Line Card
15 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing EPAs For information on verifying and troubleshooting the hardware installation, see the “Verifying and Troubleshooting the Installation” section on page 58 . Removing and Installing EPAs The Modular G...
Page 16 - To remove an EPA from your Modular Gigabit Ethernet line card, use
16 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing EPAs To remove an EPA from your Modular Gigabit Ethernet line card, use Figure 7 on page 17 as a reference and follow these steps: Step 1 Attach an ESD-preventive wrist or ankle strap and follow its di...
Page 17 - Inserting an EPA into a Modular Gigabit Ethernet Line Card
17 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing EPAs Figure 7 Removing an EPA If the EPA bay is to remain empty, install an EPA blank (Product Number MAS-EPA-BLANK=) to keep dust out of the line card and to maintain proper airflow and EMI through th...
Page 20 - and
20 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing EPAs Figure 10 Side Views - Mating the Connector of the EPA to the Line Card Step 3 Ensure that the connector guide pins are aligned. Once the connector is engaged, apply gentle pressure with your thum...
Page 21 - to ensure
21 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing EPAs Figure 12 Rear Outer Corners of the EPA (Close-up) Step 4 Press gently on the white labels in middle of the outer edge of the EPA as shown in Figure 13 to ensure that the connector is fully seated...
Page 23 - Removing and Installing GBICs; General GBIC Handling and Maintenance Guidelines, page 24
23 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing GBICs Step 6 Use a Phillips screwdriver to insert and tighten the two screws on the faceplate of the line card, 3 to 5 in-lbs, as shown in Figure 15 . Caution Apply no more than 5 in-lbs of torque when...
Page 24 - General GBIC Handling and Maintenance Guidelines; Follow these GBIC handling and maintenance guidelines:; Removing the GBIC from an Ethernet Line Card; To remove the GBIC from an Ethernet line card, follow these steps:
24 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing GBICs Caution To prevent system problems, do not use GBICs from third-party vendors. Use only the GBIC that shipped with your Gigabit Ethernet line card. These GBICs might contain an internal EPROM tha...
Page 25 - Inserting a GBIC into the Gigabit Ethernet Interface; Locate the alignment groove on the GBIC. (See the enlargement in
25 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing GBICs Figure 16 Removing and Replacing a GBIC Inserting a GBIC into the Gigabit Ethernet Interface To insert a GBIC into the Gigabit Ethernet interface, follow these steps: Step 1 Attach an ESD wrist o...
Page 26 - Removing and Installing SFP Modules; “Laser Safety” section on page 82
26 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing SFP Modules Step 4 Using moderate force, ensure that the GBIC is fully inserted into the 20-pin receptacle at the rear of the GBIC slot. The tabs on either side of the GBIC will snap into place when yo...
Page 27 - Removing a Bale Clasp SFP Module; To remove this type of SFP module, follow these steps:
27 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing SFP Modules Removing a Bale Clasp SFP Module To remove this type of SFP module, follow these steps: Step 1 Attach an ESD-preventive wrist or ankle strap and follow its instructions for use. Step 2 Disc...
Page 29 - Installing a Bale Clasp SFP Module; To install this type of SFP module, follow these steps:; Mylar Tab SFP Module
29 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing SFP Modules Step 6 Protect your line card by inserting clean SFP module cage covers into the optical module cage when there is no SFP module installed. Installing a Bale Clasp SFP Module To install thi...
Page 32 - Removing an Actuator Button SFP Module
32 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing SFP Modules Actuator Button SFP Module The actuator button SFP module includes a button that you push in order to remove the SFP module from a port. (See Figure 23 .) Figure 23 Actuator Button SFP Modu...
Page 34 - Slide Tab SFP Module
34 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing SFP Modules Step 6 Protect your line card by inserting clean SFP module cage covers into the optical module cage when there is no SFP module installed. Installing an Actuator Button SFP Module To insta...
Page 35 - Removing a Slide Tab SFP Module
35 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing SFP Modules Figure 26 Slide Tab SFP Module Removing a Slide Tab SFP Module To remove this type of SFP module, follow these steps: Step 1 Attach an ESD-preventive wrist or ankle strap and follow its ins...
Page 36 - Installing a Slide Tab SFP Module; Hold the SFP module with the hardware label facing up.
36 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Removing and Installing SFP Modules Figure 28 Removing a Slide Tab SFP Module Step 6 Place the removed SFP module on an antistatic mat, or immediately place it in a static shielding bag if you plan to return it to the factory...
Page 37 - Line Card Cable-Management Bracket
37 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Cable-Management Bracket Figure 29 Installing a Slide Tab SFP Module Note Verify that the SFP modules are completely seated and secured in their assigned receptacles on the line card by firmly pushing on each SFP mo...
Page 38 - The cable-management system consists of two separate components:
38 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Cable-Management Bracket The cable-management system consists of two separate components: 1. A cable-management tray that is mounted on the chassis. Refer to the appropriate Cisco XR 12000 Series Router installation...
Page 39 - Removing a Line Card Cable-Management Bracket; To remove a line card cable-management bracket, follow these steps:
39 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Note When shipped with spare line card orders, the cable-management bracket is not attached to the line card. You must attach the cable-management bracket to the line card before you insert the line card into the router. Caut...
Page 40 - Chassis cable-management tray
40 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Figure 32 Multiport Line Card Cable-Management Installation and Removal(4-Port OC-48c/STM-16c DPT Line Card Shown) 1 Chassis cable-management tray 3 Line card cable-management bracket 2 Velcro straps 4 Fiber cable ACTIVE CARR...
Page 41 - Installing a Line Card Cable-Management Bracket
41 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Figure 33 Single-Port Line Card Cable-Management Bracket Installation and Removal (1-Port OC-192c/STM-64c DPT Line Card Shown) Installing a Line Card Cable-Management Bracket To install a line card cable-management bracket, f...
Page 42 - Cabling and Specifications; Fast Ethernet Interface; The term
42 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications Step 2 Attach the line card cable-management bracket to the line card as follows: a. Position the cable-management bracket over the front of the line card faceplate. b. Insert and tighten the captiv...
Page 43 - Parameter
43 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications • 100BASE-FX—100BASE-T, half- and full-duplex over fiber-optic cable. Note 100BASE-TX and 100BASE-FX are commonly called 100BASE-X rather than 100BASE-T. • 100BASE-T4—100BASE-T, half- and full-duple...
Page 44 - Gigabit Ethernet Interface; This section describes the Gigabit Ethernet interface:; GBIC Laser Optical Transceiver Modules; GBIC Modules; xxxx; Type
44 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications Gigabit Ethernet Interface This section describes the Gigabit Ethernet interface: • GBIC Laser Optical Transceiver Modules, page 44 • Gigabit Ethernet SFP Modules, page 48 • 10-Gigabit Ethernet, pag...
Page 46 - Using CWDM GBICs with the 3-Port Gigabit Ethernet Line Card; GBIC Product Number
46 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications Using CWDM GBICs with the 3-Port Gigabit Ethernet Line Card The 3-Port Gigabit Ethernet line card supports CWDM GBICs. The eight CWDM GBICs available for use with an Ethernet line card are active co...
Page 47 - General CWDM GBIC Installation and Usage Guidelines; eight Gigabit Ethernet channels into a pair of single-mode fibers.; Related CWDM Documentation; Cisco CWDM GBIC Solution, Data Sheet; General Connection Rules for CWDM GBICs; Observe the following connection rules for CWDM GBICs:
47 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications General CWDM GBIC Installation and Usage Guidelines The Cisco CWDM GBIC solution has two main components: the Cisco CWDM GBICs and the Cisco OADM plug-in modules or mux/demux plug-in modules, which ...
Page 48 - Connect GBIC TX to equipment RX; Gigabit Ethernet SFP Modules; Component side of line card
48 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications • Always connect from transmit (TX) to receive (RX) when connecting GBICs to other equipment: – Connect GBIC TX to equipment RX – Connect GBIC RX to equipment TX • Optical transceivers—such as the C...
Page 50 - Fiber-Optic Interface Cables; Depending on the line card (refer to
50 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications Note Use only the SFP modules supplied by Cisco with your Gigabit Ethernet line card. Each SFP module contains an internal serial EEPROM that is security-programmed by the SFP manufacturer with info...
Page 51 - SC cable connector
51 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications • Single-mode—Generally yellow in color. • Multimode—Generally gray or orange in color. Multimode cables are multifiber cables that carry 12 channels of fiber data. Note For network applications usi...
Page 52 - Removing and Installing Fiber-Optic Interface Cables
52 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications Figure 38 Simplex LC Cable Connector Figure 39 Duplex LC Cable Connector Note Connectors on the fiber-optic cables must be free of dust, oil, or other contaminants. Before connecting the cable to th...
Page 53 - Removing Fiber-Optic Interface Cables; To remove line card interface cables, refer to
53 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications Removing Fiber-Optic Interface Cables To remove line card interface cables, refer to Figure 40 (showing one possible arrangement) and follow these steps: Step 1 Attach an ESD-preventive wrist or ank...
Page 54 - Installing Fiber-Optic Interface Cables
54 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications Figure 40 Disconnecting Line Card Interface Cables Installing Fiber-Optic Interface Cables Use two simplex SC or LC connectors or one duplex SC or LC connector (refer to Figure 41 on page 55 and Fig...
Page 56 - Cleaning Fiber-Optic Connectors; TX connector
56 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications Figure 42 Attaching Simplex or Duplex Fiber Cables (Line Card Port or GBIC) Note The fiber-optic connectors must be free of dust, oil, or other contaminants. Carefully clean the fiber- optic connect...
Page 57 - If a CLETOP cleaning cassette is not available, follow these steps:; Removing and Installing RJ-45 100BASE-T Copper Cable
57 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Cabling and Specifications The connection quality depends on two factors: the type of connector and the proper cleaning and connection techniques. Dirty fiber connectors are a common source of light loss. Keep the connectors ...
Page 58 - Removing RJ-45 Cables; To remove line card cables, follow these steps (refer to; Installing RJ-45 Cables; Verifying and Troubleshooting the Installation; Initial Boot Process, page 59
58 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Verifying and Troubleshooting the Installation Removing RJ-45 Cables To remove line card cables, follow these steps (refer to Figure 44 on page 58 ): Step 1 Attach an ESD-preventive wrist or ankle strap to your wrist and foll...
Page 59 - Troubleshooting the Installation, page 64; Initial Boot Process; no shutdown; Status LEDs; Gigabit Ethernet Status LEDs; “Product Overviews” section on page 4
59 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Verifying and Troubleshooting the Installation • Troubleshooting the Installation, page 64 Initial Boot Process Note Many new line cards are designated as administratively down by default. Status LEDs are off until you config...
Page 60 - Alphanumeric LEDs; LED
60 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Verifying and Troubleshooting the Installation Alphanumeric LEDs Ethernet line cards have two four-digit alphanumeric LED displays at one end of the faceplate, near the ejector lever, that display a sequence of messages indic...
Page 61 - LED Display; nnnn
61 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Verifying and Troubleshooting the Installation Table 18 Alphanumeric LED Messages During a Typical Initialization Sequence LED Display 1 Meaning Source MROM nnnn MBus microcode execute; nnnn is the microcode version number. M...
Page 64 - Troubleshooting the Installation
64 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Verifying and Troubleshooting the Installation Troubleshooting the Installation Note Many new line cards are designated as administratively down by default. Status LEDs are off until you configure the interfaces and use the n...
Page 65 - Line Card Memory; This section contains information about the following:; Line Card Memory Locations; Memory removal and installation instructions are found in the
65 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory Note If you perform online insertion or removal of the GBIC or SFP without shutting down the interface, a warning message is displayed on the console device. Line Card Memory This section contains information...
Page 66 - ISE Line Card Memory Locations
66 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory Engine 2 Line Card Memory Locations Figure 45 shows the DIMM socket locations on an Engine 2 line card. This line card is equipped with eight DIMM sockets: • Two route memory DIMM sockets • Two pairs of packe...
Page 67 - Route memory SODIMM0
67 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory Figure 46 ISE Line Card Memory Locations 1 Route memory SODIMM0 3 Four packet memory SODIMM sockets (not field serviceable) 2 Route memory SODIMM1 4 Four TLU/PLU memory SODIMM sockets (not field serviceable) ...
Page 68 - Two pairs of packet memory DIMM sockets (not user serviceable); Ethernet Line Card Route Memory Options; modules used for upgrading route memory on Ethernet line cards.; Total Route Memory Cisco Product Number
68 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory Engine 4 Line Card Memory Locations Figure 47 shows the DIMM socket locations on an Engine 4 line card. These line cards are equipped with five DIMM sockets: • One route memory small-outline DIMM (SODIMM) soc...
Page 69 - Router Memory Replacement Instructions; Ethernet Line Card Packet Memory Options; Removing and Installing Line Card Memory
69 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory If you are upgrading or replacing line card route and packet memory, refer to the Cisco XR 12000 Series Router Memory Replacement Instructions publication for installation procedures and the most up-to-date m...
Page 70 - Instructions are in the following sections:; Removing a DIMM; To remove a DIMM from a line card, follow these steps:; Use the socket release levers to eject the DIMM.
70 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory – Size of the DIMMs in the transmit buffer need not match the size of the SDRAM DIMMs in the receive buffer. – DIMMs must be 3.3V devices. Instructions are in the following sections: • Removing a DIMM, page 7...
Page 71 - Installing a DIMM
71 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory • For a socket with dual release levers (see Figure 48 ), pull down both levers at the same time to eject the DIMM. or • For a socket with a single release lever (see Figure 49 ), pull the lever to eject the ...
Page 72 - Removing a SODIMM; Locate the route memory socket on the line card.
72 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory Figure 50 Handling a DIMM Caution When inserting DIMMs into a socket, apply firm, but not excessive, pressure. If you damage a DIMM socket, you must return the line card for repair. Step 6 Gently insert the D...
Page 74 - Installing a SODIMM; To install a SODIMM module, follow these steps:
74 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory Figure 52 Moving the Plastic Latch Away from the SODIMM Step 6 As the SODIMM is released, it positions itself at a 45-degree angle. Gently pull the SODIMM module out of the socket. Continue to keep the module...
Page 78 - Checking the Installation of Line Card Memory; To check the installation of line card memory, follow these steps:
78 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Line Card Memory Figure 58 Retaining Clip Completely Installed into Module Latch Checking the Installation of Line Card Memory After you install line card memory and reinstall the line card in the router, the router reinitial...
Page 79 - Regulatory, Compliance, and Safety Information; Translated Safety Warnings and Agency Approvals; Regulatory; Electromagnetic Compatibility Regulatory Statements; This section contains the following information:; FCC Class A Compliance
79 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Regulatory, Compliance, and Safety Information If the router fails to restart properly after several attempts and you are unable to resolve the problem, access Cisco.com or contact your Cisco service representative for assist...
Page 80 - Move the equipment farther away from the television or radio.; Canada; English Statement of Compliance; This class A digital apparatus complies with Canadian ICES-003.; French Statement of Compliance
80 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Regulatory, Compliance, and Safety Information Modifying the equipment without Cisco’s authorization may result in the equipment no longer complying with FCC requirements for Class A digital devices. In that event, your right...
Page 81 - Class A Notice for Hungary
81 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Regulatory, Compliance, and Safety Information Class A Notice for Hungary Class A Notice for Taiwan and Other Traditional Chinese Markets Warning This equipment is a class A product and should be used and installed properly a...
Page 82 - VCCI Class A Notice for Japan; Laser Safety; General Laser Warning, page 83
82 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Regulatory, Compliance, and Safety Information VCCI Class A Notice for Japan Class A Notice for Korea Laser Safety Single-mode Ethernet line cards (all of the line cards except 8-Port Fast Ethernet) are equipped with a Class ...
Page 83 - General Laser Warning; Obtaining Documentation and Submitting a Service Request; What’s New in Cisco Product Documentation
83 Cisco XR 12000 Series Router Ethernet Line Card Installation OL-7861-01 Obtaining Documentation and Submitting a Service Request Class 1 Laser Product Warning (Single-mode) Warning Class 1 laser product. Class 1 LED Product Warning (Multimode) Warning Class 1 LED product. General Laser Warning Wa...
