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SRP500 ADSL Configuration for Telmex



This  is the SRP500 configuration for Telmex (Mexico) ADSL Services, big  thanks to Rogelio Valtierra.

Dynamic IP Address assignment

Below  is the configuration for Telmex ADSL  Service using dynamic IP  Address:

  • Internet Connection Type: PPPoE - PPP over Ethernet
  • ATM  PVC: Static
  • VPI: 8, VCI: 81 (as  indicated by Telmex)
  • Username:  <as indicated by Telmex>
  • Password: <as indicated by Telmex>
  • Connection: Keepalive
  • MTU: Manual, 1492




Static  IP Address (TBC)


Version history
Revision #:
2 of 2
Last update:
‎08-28-2017 01:30 AM
Updated by:
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This is very Helpful. But I have a Question :

If a have a static ip address with Telmex, it's the same configuration? Tanks.

Cisco Employee


Unless you have been told othewise by Telmex, the configuration will be the same as above.  For PPP, addressing is generally assigned dynamically - in your case, you are always assigned the same (static) address.




Yesterday I was setting up an SRP527W with Telmex, but not work. The 2 LEDs are green (CD-DATA), username and password correctly, but Telmex did not assign a Public IP to the router. Any ideas?



Cisco Employee


Please login as admin go to quick setup -> WAN Setup and be sure that:

Encapsulation = PPPoE,

Multiplexing = LLC

VPI/VCI Autodetect o Disable

and most important:




Rogelio V.

This is my current settings and it worked yesterday (Dynamic IP Address assignment over Telmex) :

Quick Setup - - > Basic Configuration Setup - - > Wan Setup

Encapsulation : PPPoE

Multiplexing: VC

QoS type: UBR

VPI/VCI Auto Detect

Virtual Circuit

    VPI 8

    VCI 81

PPPoE Settings

  • Username:  <as indicated by Telmex>
  • Password: <as indicated by Telmex>
  • Connection: Keepalive
  • =====================================

    Interface Setup - - > WAN - - > Internet Setup

    DSL Modulation: ADSL2+

    MTU: Manual Size 1492


    On Wednesday I was in another city (Mexico,DF) but this settings did not work (No Internet Connection) . Then yesterday I returned to my city(Mexico,SLP), but in my office the same configuration worked properly ( Internet Connection ). WTF ? Any idea?
    Tanks Rogelio, today proves changing the multiplexing to LLC . (Whats the difference?)
    Julio Mtz
    Cisco Employee


    It is the type of encapsulation, both are pretty much the same, VC-MUX is a form of network traffic control. It is used in situations where multiplexing is preferable to switching.

    If you take a look on your old the modem, it is configured to work with LLC.

    You may try to test latest SRP520 Maintenance Release 3 (MR3)


    Rogelio V.