The Long-Reach Ethernet (LRE) switches control upstream and downstream rates on the LRE links by using configurations called profiles. You can assign profiles on a per-port or switch-wide basis.
The LRE link is the connection between the switch LRE port and the RJ-11 wall port on a LRE customer premises equipment (CPE) device such as the Cisco 575 LRE CPE or Cisco 585 LRE CPE. When the LRE switch establishes a link with the CPE, the switch downloads its profile settings to the CPE so that the switch and CPE operate with the same configuration. The LRE link is not the same as the CPE Ethernet link. For information about the LRE links and CPE Ethernet links, see LRE Port Considerations.
The LRE switches are shipped with predefined profiles (Types of LRE Profiles) categorized as public (global) mode and private (per-port) mode profiles. By default, all LRE ports on the switch are enabled with the LRE-10 private profile. This profile allows the upstream and downstream transmission rate on the LRE link to be 10 Mbps.
When assigning a profile to a LRE port, keep these considerations in mind:
To change the profile assigned to the LRE ports, use the LRE Profiles window. To display this window, choose Device > LRE Profiles.
To troubleshoot the LRE links and CPE Ethernet links:
Note: You can configure and monitor the Ethernet link on a Cisco 575 LRE CPE. However, you cannot configure the Ethernet links on a Cisco 585 LRE CPE. You can only monitor the Ethernet links on the Cisco 585 LRE CPE by using the show remote interfaces status user EXEC command.
The profiles you choose are based on the requirements of your LRE environment. For the environmental factors that can influence your LRE environment and for a complete list of guidelines for using the LRE profiles, refer to the switch software configuration guide.
Note: Avoid using the symmetric profiles when the LRE switch and CPE link need to coexist in the same cable bundle with ADSL signaling. Cross talk and interference across wire pairs in cable bundles can degrade Ethernet performance.
Note: Use the LL profiles (LRE-5LL, LRE-10LL, and LRE-15LL) with care. These profiles have the low-latency (LL) feature enabled and the interleaver feature turned off. The LL feature does not delay data transmission, but it makes data more susceptible to interruptions on the LRE link. All other profiles, public and private, have the interleaver feature enabled and the LL feature disabled. The interleaver feature provides maximum protection against small interruptions on the LRE link but delays data transmission.
Note: Use the rates and distances in this table as guidelines only. Factors such as the type of cable you use, how it is bundled, and the interference and noise on the LRE link can affect the actual LRE link performance. Contact Cisco Systems for information about limitations and optimization of LRE link performance. The net data rates in the table below are slightly less than the gross data rates displayed by the show controllers lre profile names privileged EXEC command.
Profile Name | Profile Type | LRE Link Downstream Rate (Mbps) |
LRE Link Upstream Rate (Mbps) |
Maximum Distance between the LRE Switch and LRE CPE |
PUBLIC-ANSI |
Public | 15.17 | 4.27 | 4101 ft (1250 m) |
PUBLIC-ETSI | Public | 11.375 | 4.27 | 4101 ft (1250 m) |
LRE-5 |
Private | 5.69 | 5.69 | 4921 ft (1500 m) |
LRE-10 (default) | Private | 11.375 | 11.375 | 4101 ft (1250 m) |
LRE-15 | Private | 15.17 | 17.06 | 3445 ft (950 m) |
LRE-10-1 | Private | 11.38 | 1.43 | 4101 ft (1250 m) |
LRE-10-3 |
Private | 11.38 | 2.87 | 4101 ft (1250 m) |
LRE-10-5 | Private | 11.38 | 5.69 | 4101 ft (1250 m) |
LRE-5LL |
Private | 5.69 | 5.69 | 4921 ft (1500 m) |
LRE-10LL | Private | 11.375 | 11.375 | 4101 ft (1250 m) |
LRE-15LL | Private | 15.17 | 17.06 | 3445 ft (1050 m) |
"Configuring
the Switch Ports," Catalyst 2900 XL and Catalyst 3500 XL Software Configuration
Guide