The ISDN4Linux CVS repository can be accessed in several ways.
Anonymous access using the pserver method with any cvs client
Use the following commands:
cvs -d :pserver:firstname.lastname@example.org:/i4ldev login
cvs -d :pserver:email@example.com:/i4ldev co isdn
When asked for a password during login, enter "readonly" (without the quotes).
Instead of isdn you also can check out other modules like isdn4k-utils,
mISDN, mISDNuser, NGC4Linux or web For a more detailed description, have a look into the FAQ.